15.Have you wondered why different animals or pests have their particular colours?Colours in them seem to be used mainly to protect themselves.
Birds,especially seagulls are very fond of locusts (蝗蟲),but birds can't easily catch locusts because locusts change their colours together with the change of the colour of crops.When crops are green,locusts look green.But when crops are ripe,locusts take on exactly the same brown colour as crops have.Some other pests with different colours from plants are usually easily found and eaten by their enemies.So they have to hide themselves in terror for lives and appear only at night.
If you study the animal life in any part of the world,you will find the main use of colouring is to protect them.Bears,wolves and other beasts move quietly through forests.They are usually invisible(can't be seen) to the eyes of hunters,because they have the colour much like the bark(樹皮)of trees.
An even more strange act remains to be noticed.A kind of fish living in seas can send out a kind of very black liquid when it faces danger.While the liquid is over,its enemies cannot find it,and it quickly swims away.Thus,it has existed up to now though it is not powerful at all.
25.This passage mainly talks aboutD.
A.the change of colour in locusts
B.a(chǎn)nimals or pests can dye(染色)themselves different colours
C.how a certain sea fish protects itself
D.the protective colour of animals and pests
26.Locusts are pests but they aren't easily wiped out by their enemies becauseA.
A.they change colors with the crops
B.they are dangerous to their enemies
C.they fly very fast
D.they are powerful enough
27.The pests that have different colours from plants usually appear at night becauseA.
A.their enemies can easily find them and eat them
B.they have the habit of coming out in darkness
C.it's easy for them to destroy plants in darkness
D.birds take their rests when night comes
28.A certain fish living in seas has lived through millions of year becauseC.
A.it is the most powerful in the sea
B.no other fishes can swim as fast as it can
C.it can send out a kind of liquid which makes its enemies unable to find it
D.the liquid it sends out can kill its enemies.
分析 這篇短文主要介紹了為什么不同的動物或害蟲有其特殊的顏色.它們的顏色主要用于保護(hù)他們自己.作者列舉了蝗蟲,獅子,魚等動物說明這一觀點
解答 25-28 DAAC
25.D 主旨大意題.文章主要談?wù)摰氖莿游锸褂妙伾珌肀Wo(hù)自己的問題,故選D項.
26.A 細(xì)節(jié)理解題.根據(jù)第二段提到Birds,especially seagulls are very fond of locusts (蝗蟲),but birds can't easily catch locusts because locusts change their colours together with the change of the colour of crops.蝗蟲可以把身體的顏色與莊稼變成一樣的顏色,不容易被鳥發(fā)現(xiàn),故選A項.
27.A 細(xì)節(jié)理解題.根據(jù)短文第二段最后一句"So they have to hide themselves for lives and appear only at night."的描述可知,這些動物白天躲藏起來,晚上出來活動,故選A項.
28.C 細(xì)節(jié)理解題.根據(jù)短文最后一段A kind of fish in the sea can give out a kind of black liquid(液體)when the fish face danger.The liquid spreads over quickly,so they cannot be found by their enemies and can quickly swim away.That is why they can live safely though they are not strong at all.的描述可知,魚能夠保持安全是因為它發(fā)出來的液體能幫它躲避敵人,故選C項.
點評 學(xué)生需要認(rèn)真閱讀原文,把握文章大意,對文章脈絡(luò)有整體的了解,能仔細(xì)查找文中細(xì)節(jié),并能根據(jù)文章內(nèi)容進(jìn)行合理的推測判斷.