题目内容：

When people are dirty, they take a bath or a shower. Animals don’t have soap, 1. they do keep themselves clean. Many animals with hair, such 2. dogs and cats, keep themselves clean by licking(舔) their hair. They also use their 3. (tooth) to pull out small dirty things from their hair. When they lick their hair, it is almost as if they are 4. (use) a wet brush to clean themselves.

Birds take baths to stay clean.5.  (one) they walk through water that is not deep. Next they beat their wings(翅膀) to dry themselves. Birds also take sand(沙子) baths on the ground. It is 6. (think) that they do this to drive away parasites(寄生虫)．

Even fish need cleaning. Fish have very little parasites that live in their mouths. Some fish live 7.  eating these parasites off other fish. Such fish are called “cleaner fish”. Larger fish will open their mouths so that the cleaner fish can get in to clean.

Some animals that live in 8. (group) clean each other, such as monkeys. They often clean one another. One monkey may clean 9.  area that the other monkey can’t reach. How 10. (interest) it is!