题目内容：

We sometimes call the lion “the king of the jungle” Because it is stronger and more dangerous than other animals. 1.It is the highest animal in the land food chain.

In the sea, the shark is one of the animals at the top of the food chain. It can swim faster than most other sea animals2.

3.People are! We are not the biggest or fastest. but we are the cleverest. We could not run faster than cheetahs, so we invented cars and now we can move the fastest. We could not fight better than lions. so we invented guns. Now we can hunt the best. People's inventions are clever, but they can be dangerous, too. For example, people invented factories, and now they make the air and rivers dirty. 4.Dirty rivers kill fish. Then bears cannot eat the fish and die. If we kill one part of the food chain. other parts also die. Remember that we are a part of the food chain. so we are in danger, too! 5.We should and we could do something for the world!

A.Protecting animals is protecting ourselves!

B.And it can use its big teeth to eat them.

C.This can make terrible changes.

D.What is at the top of the world's food chain?

E.It can run faster than many animals and it can hunt the best.