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________.

2.How can pests with different colors from plants keep out of danger?

3.Bears and lions can keep safe because _________.

4.Why can the kind of fish live up to now?

5.Which is the best title for this passage?

选词填空

You may think there is nothing but sand in the desert of the world, but it is not true. In the desert we can   76   stones. We can see hills, too. There is a little rain in the   77   , but it is not   78  for most plants.

　　The animals are   79  to the desert people in many ways. The desert people eat the meat and drink the milk of the animals. They use their skins to    80  shoes, water bags and even tents(帐篷). They use the camels(骆驼) for   81  things.

The people of the desert have to keep    82  from places to place. They must always look for grass or desert plants for their animals. They usually live in the tents. When there is mo more food for their animals, they take down their tents, put them on the camels and move to    83  place. The desert people are very   84 . No man in the desert would ever refuse to help the people in   85  and give them food and water