1. The plant is now in danger of extinction.

2. The breed was on the verge of extinction.

3. Many species are doomed to extinction.

4. Pandas are on the margin of extinction.

5. The species was doomed to extinction.

6. Modern farming methods have led to the total extinction of many species of wild flowers.

7. Through the total fading away and extinction of craving, decay and death, sorrow, lamentation, suffering, grief, and despair are extinguished.

8. The mountain gorilla is on the verge of extinction.

9. The centuries-old ritual seems headed for extinction.

10. Will technology in music drive creativity to extinction?

11. Hundreds of tree species face extinction.

11. try its best to gather and make good sentences.

12. They were hunted almost to extinction .

13. These animals are now on the verge of extinction.

14. The creature is on the threshold of extinction.

15. Their traditional way of life seems doomed to extinction.

16. Many species are now threatened with extinction.

17. Mountain gorillas are on the verge of extinction.

18. The condor was in grave danger of extinction.

19. Are whales doomed to extinction?

20. Many endangered species now face extinction.

21. Many wild plants are under threat of extinction.

22. The island's way of life is doomed to extinction.

23. The dormouse in Britain may face extinction if ancient woodland continues to disappear.

24. Conservationists are trying to save the whale from extinction .

25. The loggers say their jobs are faced with extinction because of declining timber sales.

26. An operation is beginning to try to save a species of crocodile from extinction.

27. In the 19th century, inbreeding nearly led to the extinction of the royal family.

28. A comet colliding with the earth may have caused the mass extinction of the dinosaurs.

29. 30 percent of reptiles, birds, and fish are currently threatened with extinction.

30. The society was set up to preserve endangered species from extinction.

1. The plant is now in danger of extinction.

2. The breed was on the verge of extinction.

3. Many species are doomed to extinction.

4. Pandas are on the margin of extinction.

5. The species was doomed to extinction.

6. Modern farming methods have led to the total extinction of many species of wild flowers.

7. An operation is beginning to try to save a species of crocodile from extinction.

8. The island's way of life is doomed to extinction.

9. All water used by the fire - brigade for fire extinction purpose is supplied free by an act of Congress.

31. We may live to see the extinction of the whale.

32. They have driven the rhino to the edge of extinction.

33. All water used by the fire - brigade for fire extinction purpose is supplied free by an act of Congress.

34. Some people predict the extinction of family life as we know it today.

35. Out of 329 parrot species, 30 now face extinction.

36. It was saved from total extinction by two developments.

37. The howlers were skirting the scary precipice of extinction.

38. The Scarlet Macaw is in imminent danger of extinction.

39. Some would say it is close to extinction.

40. Out of 329 parrot species, 30 face extinction.

41. The big cat has been hunted to near extinction.

41. is a online sentence dictionary, on which you can find excellent sentences for a large number of words.

42. They, too, are all being driven towards extinction.

43. Many are now threatened with extinction.

44. The inefficient and unprogressive were penalized by extinction.

45. It is unlikely to reach extinction.

46. This trade may be driving some species to extinction.

47. Greenpeace believes that whales are in danger of extinction.

48. This not withstanding, it is doubtful that pit culture is on the brink of extinction.

49. And in the 1960s, the breed was on the verge of extinction.

50. The latter is a recipe for chaos, anarchy and mutual extinction.

51. That era, however, was allegedly on the brink of extinction.

52. The bug obtains its energy by chemical means and may drive smelters to extinction.

53. But extinction is for ever and it doesn't do the world much good to save a seed for a year or two.

54. Large numbers of rare and beautiful Alpine plants are threatened with extinction.

55. When Lord Leverhulme abandoned Lewis, the crofting villages seemed doomed to a steady decline and eventual extinction.

56. Apparently, the last chance to avoid the extinction of a formerly widespread and prosperous species had been lost.

57. I saw then that we shall die, wish ourselves into extinction, unless we find a new course.

58. Epistandard rates of evolution are required to make up the loss through extinction.

59. In a purely ecological sense, this wave pattern describes a situation that might be called suspended extinction.

60. The belugas of the St Lawrence may now number only 400, and this local population is almost certainly doomed to extinction.

61. Among the Scandinavian settlers of the Upper Mississippi Valley, leprosy had declined to near extinction.

62. The alligator, though pursued for its hide and much reduced in numbers, is not in present danger of extinction.

63. The Butterfly Conservation Society says the information could help save some of the rarest examples from extinction.

64. Only the egrets, spoonbill, and least tern, however, faced actual extinction before help arrived.

65. The original passenger pigeon was driven into extinction from a population that reached almost ten million at one point in time.

66. If it were as bad as its critics contend, our society would be teetering on the edge of extinction.

67. No market for furs equals no shops like that one, equals no fur trade, no species extinction.

68. If extinction is repeated, the behavior will eventually disappear or become extinct.

69. In their place were a strange land, a strange people, and the ever-present possibility of violence and extinction.

70. Appendix I of the convention lists species in danger of extinction.

71. Extinction might be expected to occur if your local pub stopped selling your favourite drink.

72. He waxed vehement about dinosaurs and extinction,(http:///extinction.html) about continental drift and the good old Galapagos finch.

73. That beer swilling, tattooed, sexist monstrosity which is fast heading into extinction anyway.

74. The financial crises of the 1920s and the Great Depression of the 1930s had brought capitalism to the edge of extinction.

75. The brewers have at last woken up to the fact that their high-street shops have become dinosaurs slouching towards extinction.

76. He is at the forefront of the campaign to save the Elephant from extinction.

77. In the infrared, extinction by dust is an order of magnitude smaller than in the visible portion of the spectrum.

78. The character gaps between good species he explains by continued divergence and by the extinction of intermediate varieties.

79. How do species that colonize vents cheat the inevitable local extinction?

80. And the system faces global maritime extinction by February 1999.

81. Yet people ignore the plight of, say, the several species of bat which are on the edge of extinction.

82. In 1921, there was a huge increase in the emigration and physical extinction of households.

83. Athird disease, guinea worm, is on the brink of extinction.

84. Arms races sometimes culminate in extinction, and then a new arms race may begin back at square one.

85. There are between 80,000 and 100,000 species of trees, of which 8,000 are threatened with extinction.

86. The large numbers of wild orchids being traded threatens some species with extinction.

87. Indeed the most dramatic example of mass extinction known to biology has been caused by the introduction of an alien species.

88. They understand the dangers that lurk there, the balance between survival and extinction.

89. The passing bell is sounding for the mass extinction of species.

90. To an outsider, our raft would have appeared already to be on the verge of extinction.

91. Whatever caused the extinction, it is not soft skin that determined survival.

92. But 25 native species are endangered, seven to the verge of extinction.

93. Less clear is the question of whether mushrooms can be hunted to extinction.

94. Wolves, which are clean and beautiful, have been hunted almost to extinction because they are seen as dangerous.

95. This meant that they had now gained a tremendous advantage over the reptiles, even causing the extinction of many of them.

96. By contrast, a cruiser is utterly directed, as Schopenhauer might have put it, towards the extinction of his desire.

97. Over the period since 1945 as a whole, other beasts proved mammoths - of elephantine size but doomed to extinction.

98. Loss of beachfront habitat and predation by domestic cats and introduced red foxes pushed the least tern to the brink of extinction.

99. Many are working to save species from extinction, animals from cruelty, natural environment from destruction.

100. Bird's island haven A REMOTE Donegal island is proving a haven for a native bird threatened by extinction.

101. Several equally renowned eating places such as Drouant are also threatened with extinction.

102. But below the mirror images of arts and architecture lurks the threat of extinction - Venice is in Peril.

103. Cuvier tried to evade one disturbing implication of extinction by linking the phenomenon to his theory of catastrophic geological changes.

104. But it is not just this personality clash that is driving Solidarity-as-we-know-it to extinction.

105. There, for 20 years, she had watched helplessly as that country's wildlife was systematically hunted to extinction.

106. But weren't zoos supposed to be for studying animals, and saving species from extinction?

107. Fornication was inevitable; it was something of a relief that high unit labour costs had driven the boot man to extinction.

108. When this happens it can dramatically slash profits - and can even threaten a business with extinction.

109. Trade in the grey whale has been outlawed since 1949 because uncontrolled whaling had put it on the verge of extinction.

110. But germ lines can deteriorate and cause extinction of lineages.

111. Pen Pros: Except for personal letters, handwritten notes are withering into extinction.

112. The results are used to help the teacher to diagnose student deficiencies. extinction See also under learning: conditioned reflex.

113. Most of this trade is legal and involves species not threatened with extinction, although conservationists feel better controls are needed.

114. Secondly, they say there is no scientific evidence that whales are near extinction.

115. Ornithologists have been fighting to save the bird from extinction for the last 50 years.

116. It is not: extinction has happened millions of times before and is an exciting opportunity for science.

117. To Liberal party activists, however, it was the extinction of a lamp, the end of an era.

118. Even more probable than the extinction of humanity is a catastrophe that destroys our culture while leaving some humans still alive.

119. The oyster farming industry, already hit by recession, would face extinction should the proposals be implemented.

120. Darwinism showed that extinction was the result of physical weakness or unfitness for purpose.

121. But once established, these lines underwent predictable developments towards increasing specialization - and eventually to overspecialization and extinction.

122. The golden eagle, at one time persecuted to near extinction by game keepers, is now a strictly protected bird.

123. Henceforth this system provided the framework for his preoccupation with the problems of the extinction and origin of species.

124. About 1,000 bird species are deemed at risk of extinction, and 88 of those are parrots.

125. Environmentalists are campaigning to save the white rhinoceros from extinction.

126. The biological positivists could only propose indeterminate detention or extinction for such categories of offender.

127. Many suspected that they were a dying race, slowly passing into extinction.

128. The park is participating in an international breeding programme with several other zoological collections, to help save the race from extinction.

129. Several species have come back from the brink of extinction.

130. Under emancipation, the Negro was thought to be doomed to extinction.

131. The aurochs are thought to have been hunted to extinction in Britain during the Bronze Age.

132. One possible case of paired impacts has been widely discussed in connection with the Cretaceous extinction event.

133. The Hodges doctrine, with its limited interpretation of federal power,(http:///extinction.html) seemed well on the way to extinction.

134. Whales, too, were hunted to near extinction before the moratorium-of 1986.

135. The exact location is being kept secret to avoid poaching, which almost drove the giant clam to extinction 20 years ago.

136. Since there is a limited scope for polished versification of good sense and elegant learning, poetry declines towards extinction.

137. The end of the Triassic was marked by what is probably the third largest extinction event since the Cambrian.

138. Big species such as tuna and cod are disappearing, fished to virtual extinction in many places.

139. In some areas the vulture has vanished, with extinction possibly five years away.

140. It was a world which howled with car chases and teetered between excitement and extinction.

141. And these prized woods come from special trees, many of them threatened with extinction.

142. The virtual extinction of the dragon sister tutor should also help to allay your fears.

143. This illness now, huddling in the deck chair,() was an extinction.

144. It's thought that a comet colliding with the earth may have caused the mass extinction of the dinosaurs.

145. The cause of dinosaur extinction is still unascertainable today.

146. Crucifixion thought - form is akin to extinction.

147. Study on relationship between extinction coefficient and mass concentration.

148. And then the apparent extinction coefficient can be calculated.

149. Pleistocene glaciation caused the extinction of many species.

150. Orang are currently on the verge of extinction wildly.

151. On that scale the Hangenberg event, an extinction 359 million years ago at the end of the Devonian period, was considered a minor blip. Not any more.

152. Results showed that the extinction angle reflected the degree of anisotropy of pyrocarbon.

153. The development tendency of vacuum switch in the future is to miniaturize vacuum extinction chamber and develop high voltage vacuum switch and low voltage vacuum switch.

154. Azo dyestuff formed by (1) has great color tone, macromolecule extinction coefficient and good storage stability, so it can be made into imaging dye stuff and colorant.

155. With larger signal power, smaller probe power, suitable conversion interval and downwards conversion mode, the output extinction ratio can be enhanced.

156. There is a case of an oysterlike bivalve that evolved a more and more spiraled shell until, just before extinction, the valves could barely open.

157. Compared sequential cropping pattern ( WCSCP ), WCCCP has higher light interception amount and less light extinction coefficient.

158. The simulation model shows that, at high or medium mortality level, the probability of extinction for Chinese River Dolphin is 1. 0 or around 0. 5 within the next 100 years.

159. Our Lakota language is an Endangered Language, on the verge of extinction.

160. A cruel twist of mutation among the Theelin led to genetic incompatibility among their own kind, dooming the species to extinction.

161. These findings are consistent with other evidence that anisomycin blocks both the consolidation of original learning and extinction.

161. is a sentence dictionary, on which you can find nice sentences for a large number of words.

162. Representative elements of order Albaillellaria firstly appear in Silurian, which prosperous in Late Devonian, and extinction in end-Permian, is the characteristic group of Late Paleozoic Radiolaria.

163. Author holds liability could be counter - plea with fair use, copyright lose or extinction of prescription.

164. It was extinction by dilution, and to the ornithologists it was just as tragic as the more dramatic demise of the passenger pigeon or the Carolina parakeet.

165. Pragmatistic culture is in conformity with era taking surviving or saving the nation from extinction as theme .

166. The last chapter definitizes the concept of extinction of agent right and points out its legal results, mainly discussing exterminating reasons of legal agent right and commission agent right.

167. Function and configuration of extinction ratio testing system of pulse laser range finder are described.

168. The creature lived in Antarctica during the mass extinction at the end of the Permian period, which wiped out 95% of all life in the oceans and 70% of all land life.

169. A bigger mass extinction, at the end of the Permian period 251m years ago, killed 70% of the world's land vertebrates (and 96% of all marine animals) and paved the way for the age of reptiles.

170. The mass extinction coefficient of smoke particles is an intrinsic physical parameter to character shielding property.

171. Based on the principle of full flow extinction, this paper excogitated a pocketable opacity smoke meter.

172. "My guess is that the paddlefish and the Yangtze sturgeon are on the way to extinction already but there are other species that the reserve may be critically important for," Dudgeon warned.

173. With a number of the brands on the December list either gone or on a short-term path to extinction, 24/7 Wall St. has put together the latest version of the Ten Brands that Will Disappear.

174. The ultimate extinction of the dinosaurs 6300 years ago in the Mesozoic and Cenozoic Tertiary Paleocene.

175. The nonprofit marine conservation group Oceana recently posted a petition asking Congress to save bluefish tuna, a fish rapidly facing extinction because of unmonitored overfishing.

176. So that the dark could attempt to find a way to waylay real ascension causing earth to sink into extinction.

177. Chinese people do not subjugated, but it faces the danger of extinction.

178. To save his dynasty from extinction, Grand Duke Karl needed to find a way to preserve the Z?hringen line. Granting succession rights to his half-uncles seemed the ideal solution.

179. A trumpeter swan glides across the surface of the Yellowstone River. Trumpeter swans once faced extinction; today their numbers are rebounding.

180. The results show that the mass extinction coefficient of the hollow particles increases to a great extent when contrasted with that of the solid ones unde.

181. The extinction coefficient of the water is the sum of absorption by the water itself, by particles suspended in the water, and especially by dissolved color substances.

182. Mammoths and mastodons are both elephant-like creatures with long tusks that both faded into extinction on this continent more than 12, 800 years ago.

183. Lamarck thought there was an inherent progressive tendency driving organisms continuously towards greater complexity, in parallel but separate lineages with no extinction.

184. Blooming of Bacteria and Algae: Possible Killer of Devonian Frasnian - Famennian Mass Extinction?

185. The discovery gives conservationists hope that the fox—listed as threatened by California—may just outfox extinction overall, scientists say.

186. Blue whale of Antarrct has plunged to less than 1% of the original abundance. West Pacific grey whale hovers on the edge of extinction with just over 100 remaining.

187. Because of the confusion caused by the indiscriminate use of the term "Quagga" for any zebra, the true Quagga was hunted to extinction without this being realized until many years later.

188. The core of optical reshaping is a decision gate featuring signal extinction ratio enhancement and noise reduction.

189. The numerical simulation indicates that, larger biasing current and smaller detuning expand the dynamic range of conversion efficiency and extinction ratio, but worsen the frequency chirp.

190. Many species are in peril of extinction because of our destruction of their natural habitat.

191. Native Australian Charlie Mungulda is the only person alive known to speak that language, one of thousands around the world on the brink of extinction.

191. Wish you can benefit from our online sentence dictionary and make progress day by day!

192. But at higher temperature, PD extinction voltage is seen clearly.

193. Some scientists think that massive ocean extinction events in the past caused Earth’s carbon cycle to fluctuate wildly for millions of years afterwards.

194. Article 6 The establishment, transference or extinction of ship mortgage or bare boat chartering shall be registered at the Ship Registration Administration.

195. This includes Bring Back the Salmon, which helps the return of Atlantic salmon to Lake Ontario after its local extinction over 100 years ago.

196. It shows that micro-discharge extinction potential drops along inverted catenary with the reduction in angle of contact.

197. The animals were ruthlessly hunted to the verge of extinction.

198. The theory is the brainchild of Professor Bill Napier, from Cardiff University, who says it explains the mysterious period of extinction around 11, 000 BC.

199. And then we draw a conclusion by lucubrating that the influence of the extinction ratio is not linear with system homodyne crosstalk requirements in the case of a single crosstalk signal.

200. Rodians evolved as hunters, killing much of the wildlife and predacious species on their planet to extinction.

201. "Before the mass extinction, most of the foraminifera species were comparatively large, very flamboyant, very specialized, very ornate, with many chambers, " Keller explained.

202. Theories about the extinction of dinosaurs are still highly conjectural.

203. Zoologists failed to find a Yangtze River dolphin during a survey of the creature's historic range, the first likely extinction of a large vertebrate in 50 years.

204. While the number of spoken languages continues to decline, at least one new one has been added to the inventory, though Koro too is on the brink of extinction.

205. As the coastal waters were heavily fished, the seals remained on the southern-most island and the giant moa(a huge flightless bird)was eventually hunted to extinction.

206. At the end of the Ordovician period, 440m years ago, a mass extinction event wiped out almost all corals and fish, and 25% of all families of creatures.

207. The crabs the children catch can be named in an instant by Zheng Qinghai. The majority are common to the region, but the endemic species of Taiwanese fiddler crab is facing extinction.

208. Mr. Gao Chuan-chi asked if the author was foretelling the species replacing human being after its extinction. Mr.

209. This is how Cornish and some dialects of Scottish Gaelic slipped into extinction.

210. The building of flamelet database is very important a step in improving flamelet model. It includes improving the exactness and completeness of combustion states as well as extinction limit capturing.

211. Droplet ignition and extinction in practical combustors are strongly influenced by forced convection and turbulence.

212. During the voltage recovery period after the extinction of fault arc, the amplitude and phase of transient fault voltage is essentially different from those of permanent fault voltage.

213. Indeed, I found afterwards that horses, cattle, sheep, dogs, had followed the Ichthyosaurus into extinction.

214. This animal spread across the massive, ancient continent of Pangea after the end of the Permian Extinction.

215. Females become rare, causing fewer young dinosaurs to be born and species to dwindle to extinction.

216. The molecular extinction coefficient is equal to the ratio of the log of the intensity of the incident and emergent light.

217. Set mainly on the Jurassic undercliff at Lyme Regis, the novel plays with the idea that the Victorian bourgeoisie — and the kind of novel that represents it — is on the brink of extinction.

218. The beauty of the base-closing bill...is that is takes Congress off the hook. A blue-ribbon commission would pick the bases marked for well-deserved extinction.

219. A new type of method for estimating extinction efficient boundary values with least square fitting for inversion of slant angle lidar measurement is reported.

220. Extinction and colonization account for the depauperate flora and fauna of islands when compared to the adjacent mainland.

221. The economists say the competition otter to the brink of extinction.

222. "What's striking is how fast the extinction was," says paleontologist Douglas Erwin of the Smithsonian National Museum of Natural History in Washington, D.C.( ), a co-author on the paper.

223. No, but striped hyena are now rare due to hunting and habitat destruction. Populations in North Africa and Arabia are in danger of extinction.

224. With rising temperatures, this endangered reptile could produce all male offspring by 2085, guaranteeing its extinction, a new study finds.

225. One of the most important causes of extinction is loss of habitat.

226. Cloning saves the endangered species from extinction and keeps the ecological balance.

227. However, the invasion of the so-called elpistostegalians—distant relatives of the coelacanth—"got wiped out by these extinction events, " McGhee explained.

228. American national emblem the bald eagle on the verge of extinction and under on and on.

229. The optical and infrared data also measured the extinction in these molecular gas clouds.

230. The Mass specific extinction coefficient is a fairly universal constant, so can be left at the default value.

231. Infrared extinction ability and application of tiny graphite powder in combustible anti - infrared smoke screen were studied.

232. According to "General Surveys", the effect of negative prescription is composed of three doctrines: extinction of subjective right, extinction of claims and occurrence of right to counterargument.

233. In the extinction of animal, the thylacine is the worst.

234. Excessive aquaculture and cultivation were the most important causes of extinction of aquatic fern.

235. Its index of refraction is the same as the common sample, but the extinction coefficient is smaller.

236. The story of the Passenger Pigeon is one of the most tragic extinction stories in modern times.

237. The positive invariant property, eventual boundedness, non-persistence, permanence, extinction, and globally asymptotic stability of the system was investigated.

238. International financial monopoly capital, the extinction of the middle class, with distinctive features of the international.

239. Even, noble attempts to save endangered species from extinction by nuclear transfer have been tried, and in some cases resulted in live animals (wild cats, gaur and mouflon sheep).

240. The Tasman booby (Sula tasmani), a subspecies of the masked booby (Sula dactylatra), was nearly eaten into extinction at two points in history.

241. In the algorithm, the boundary value of extinction is calculated by fitting Lidar return signal in cloudless weather.

242. These findings further suggest that humans may have developed complex cognition that can aid in regulating emotional responses while utilizing phylogenetically shared mechanisms of extinction.

243. We shall simply be resigning ourselves to extinction unless we carry on the four modernizations.

244. The relations between extinction ration, half wave voltage and electrode structure has been analyzed and calculated with transfer matrix theory and effective index method.

245. Many of the best-documented cases of individual species being driven to extinction or near-extinction by humans are those of over-exploitation.

246. The Triassic period ended 210m years ago with another mass extinction of land animals and sea creatures.

247. If the enterprises do not have the idea of development financing, no financing development strategy, then companies involved in the wave of capital and the risk of extinction is extremely widespread.

248. Already almost all Californian Native American languages are in danger of extinction.

249. The benthic extinction event (BEE) and larger foraminifera turnover (LFT) during the Paleocene-Eocene transition constitutes an important step in Paleogene larger-foraminifera evolution.

250. Hunted to near extinction in parts of Scandinavia, the arctic fox is plentiful elsewhere, including here in Iceland.

251. It uses reflection of object(/extinction.html), atmosphere extinction coefficient of two laser wavelengths and others key technology to improve the observational distance of laser radar.

252. Skinner (1904-1990) built upon Thorndike's ideas to construct a more detailed theory of operant conditioning based on reinforcement, punishment, and extinction.

253. The extinction of key species could have cascading effects throughout the food web.

254. Results The extinctive time of erythema in acne patients was shortened and the extinction of pigment expedited after treated in combination with dressing collagen.

255. In the neoteric and modern civil laws descending from Roman law, drawing has shown its value as one of reasons and means for the extinction of debt.

256. Many species have been shot to the verge of extinction.

257. The Cretaceous extinction was like a terrible streak of bad luck lasting millions of years.

258. Further more, the analysis of the coupling efficiency and extinction ratio in different coupling angle and offset distance are proposed in this dissertation.

259. Proliferative vitreoretinopathy (PVR) is a serious oculopathy. It often results in visual extinction, or even loss of sight.

260. Release the holographic agreements to tie into the extinction planes , and ascension may come forth.

261. Light-blockage particle counter realizes take count of the number of particles by the particle's extinction for light.

262. A new study shows the apparent mass extinction was due instead to a combination of climate change, habitat loss as well as human impact.

263. If there were a single, remediable cause of the honeybee die-off, the question of possible extinction would lose much of its force.

264. Was There a Mass Extinction of Land Plants at the Permian - Triassic Boundary ( PTB )?

265. Ultra-transparent, super-insulating: its almost glass-like transparency, but also self-destroy the nature of fire extinction, fire prevention materials for the best light.

266. But the Mahayana tradition separated them and considered that nirvana referred only to the extinction of craving (passion and hatred), with the resultant escape from the cycle of rebirth.

267. Traditional British delicacies such as bath chaps, jugged hare and brawn are under threat of extinction as youths in the kingdom haven't even heard of them, a survey showed.

268. An extinction coefficient UV method for determination of content uniformity of famotidine for injection was established.

269. It may not be long before we witness the extinction of one of the world's six species of tigers, the Amur (or Siberian) tiger (Panthera tigris altaica).

270. Light - blockage particle counter realizes take count of the number of particles by the particle's extinction light.