In nature, you may see many insects (昆虫）and animals of different colors. Have you ever wondered why?
Locusts are super delicious food for birds,but it is not always an easy job for birds to catch them.It is neither because locusts are good jumpers or runners nor because they are smarter than their enemies. The reason is that the colors of locusts change with the colors of crops(庄稼). When crops are young,locusts look green. But when autumn comes, locusts change to the yellow and brown color as crops do.
Brown bears,tigers and other animals move quietly through forests. They can’t be seen easily by their enemies. This is because they have colors similar to the trees. For the same reason, polar bears that live on a land of snow and ice are white. Butterflies and bees living among the flowers are colorful like flowers. Soil insects are mostly  dark-colored and they live under the soil(土壤） in a dark and wet environment. However, insects with colors different from plants can easily be found and eaten by others. So in order to survive,they have to hide themselves in the daytime and appear only at night.
Have you ever noticed some even stranger acts? The ink fish in the sea can send out some very black ink when it faces danger. As the ink spreads over , its enemies will find themselves suddenly in a dark world. At the same time the ink fish immediately swims away. That is how it keeps itself safe though it is not strong at all.
It is not easy for birds to catch locusts because____________.

A．locusts are good runners

B．locusts can jump very high

C．locusts are smarter than birds

D．locusts can change their color

According to the passage, most soil insects_________

A．do not have bright colors

B．change their colors with the soil

C．do not live in a dark and wet environment

D．Eat colorful insects like butterflies and bees

What’s the meaning of the underlined word”survive” in the passage

A．繁殖

B．产卵

C．觅食

D．生存

The ink fish_______so that its enemies will not see it

A．changes its color	B．makes the water around it black
C．appears only at night	D．hides itself in the sea rocks

What is the main ides of this passage

A．Some insects and animals have different skills.

B．Some insects and animals are clever than we think.

C．Some insects and animals use colors to protect themselves.

D．Some insects and animals can get used to the environment easily.