阅读与表达。

     This is Andy's room. It is not very big, but the window is big and the bedroom is bright. We can see some

pictures and a nice kite on the walls. Andy's bed is small. A clock is on the table and some bottles of milk are

under it. A desk is near the window. The desk is small. Andy puts all her books in the desk and some clothes in

it, too. There are some flowers on Andy's desk. Some are purple, some are red, some are yellow and the others

are white. They are very nice. She likes to help others.

根据上文内容填空

1. Andy's books are ______________. We can't see them.

2. The flowers on the desk have ____________colors.

3. Andy's bedroom is not _____________. There are many things in it.

4. __________________ are on the walls.

5. There is a desk ____________________.

下列哪种气体不能用于超声造影()

A．空气

B．二氧化碳气体

C．氧气

D．纯氮气体

E．氟碳气体