Do you know why different animals or pests(昆虫) have their special colors? Colors in them seem to be
题目
Do you know why different animals or pests(昆虫) have their special colors? Colors in them seem to be used mainly to protect themselves.
Some birds like eating locusts(蝗虫), but birds cannot easily catch them. Why? It is because locusts change their colors together with the change of the colors of crops(庄稼). When crops are green, locusts look green. But as the harvest time comes, locusts change to the same brown color as crops have. Some other pests with different colors from plants are easily found and eaten by others.So they have to hide themselves for lives and appear only at night.
If you study the animal life, you'll find the main use of coloring is to protect themselves. Bears, lions and other animals move quietly through forests. They cannot be easily seen by hunters(猎人). This is because they have the colors much like the trees.
Have you ever noticed an even stranger act? A kind of fish in the sea can send out a kind of very black liquid(液体)when it faces danger.While the liquid spreads over(散开), its enemies(敌人) cannot find it. And it immediately swims away. So it has lived up to now though it is not strong at all.
1. From the passage we learn that locusts________.
A. are small animals
B. are easily found by birds
C. are dangerous to their enemies
D. change their colors to protect themselves
2. How can pests with different colors from plants keep out of danger?
A. They run away quickly.
B. They have the colors much like their enemies.
C. They hide themselves by day and appear at night.
D. They have to move quietly.
3. Bears and lions can keep safe because______.
A. they have the colors much like the trees
B. they move quietly
C. they like brown and gray colors
D. they live in forests
4. Why can the fish mentioned in the last paragraph live up to now?
A. Because it is very strong.
B. Because the liquid it sends out can help it escape from its enemies.
C. Because the liquid it sends out can kill its enemies.
D. Because it swims faster than any other fish.
5. Which is the best title for this passage?
A. The Change of Colors for Animals and Pests
B. Colors of Different Animals and Pests
C. The Main Use of Colors for Animals and Pests
D. Some Animals and Pests
答案
答案依次为D C A B C 非常确定
举一反三
已知函数f(x)=x,g(x)=alnx,a∈R.若曲线y=f(x)与曲线y=g(x)相交,且在交点处有相同的切线,求a的值和该切线方程.
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
最新试题
热门考点
- 不向命运低头的名人事例
- I see a lot of money every day because I work in a
- 设函数f1(x)=x1/2 f2(x)=x-1 f3(x)=x2 (注:x后的是指数),则f1(f2(f3(2012))=?
- 已知a是最小的正整数,b、c是有理数,并且有|2+b|+(3a+2c)的平方等于0.求abc等于几
- 19999.9+1999.9+199.9+19.9+1.9怎么巧算
- 古诗中不同的诗人,不同的送别方式.
- 已知二次函数y(x) =x平方+bx+c满足f(0)=3,f(-1)=3 ,求(1)b,c的值.(2)若f(x)大于等于0 求x 的解集
- 天平砝码:100克一个,50克一个,20克两个,10克一个,5克一个,游码最大度数为5克,这天平最大称量为?克
- 夏天柏油路上的现象求解释
- 秋思改编一个小故事怎么写