题目内容：

用a或an填空。

1.That is ____ apple and it is nice.

2.—What's that?

—It's ____ computer.

3.This is ____ English book and that is ________ math book.

4.Here is ____ cup for you.

5.—Is it ____ orange?

—Yes, it is.

6.—Is that ____ pen?

—No, it isn't.

7.In the picture, there is ____ A and ____ B.