简答题 He said that he had left his umbrella in the library.

简答题 A teacher should have patience in his work.

简答题 A friend of mine from high school is working in England now.

简答题 A good memory is a great help in learning a language.

简答题 Air is all around us.

简答题 After I get home, I'll call you.

简答题 A lot of natural resources in the mountain area will be exploited and used.

简答题 A dog is always well-known as a clever and friendly animal.

简答题 A sign at the bus stop helps you to know which bus to take.