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. 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.
From the passage we learn that locusts________.
A. are small animals
B. are easily found by birds
C. change their colors to protect themselves
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.
What does the underline phrase “crops” mean?
A. 灌木丛                       B. 庄稼                     C.水草
Which of the following is NOT TRUE?
A. Bears and lions can keep safe because their colors are like the trees
B. Some pests can’t change their colors with the crops.
C. The kind of fish can live up to now because its black liquid can kill its enemies.
Which is the best title for this passage?
A. The Change of Colors for Animals and Pests
B. The Main Use of Colors for Animals and Pests
C. Colors of Different Animals and Pests