阅读理解。
Do you know why different animals or pests (害虫) have their special colors？Colors on them seem to be used mainly (主要地) to protect themselves.
Some birds like eating locusts (蝗虫), but birds cannot catch them easily. Why? Because locusts change their colors according to 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 (隐藏) themselves and appear (出现) only at night.
If you study 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 colors much like the trees.
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 out, its enemies (敌人) cannot find it, so it can escape (逃跑) at once. That is why it can live long, 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 grey colors
D. they live in forests
4. Why can the kind of fish live long?
A. Because it is very big and strong.
B. Because it can send out a kind of very black liquid to help it escape from its enemies.
C. Because it can send out a kind of liquid to kill its enemies.
D. Because it swims faster than any other fish.
5. Which is the best title(标题) of this passage?
A. The Change of Colors for Animals and Pests.
B. Colors of Different Pests.
C. The Main Use of Colors for Animals and Pests.
D. Some Animals and Pests.
