新概念英语测试(Lesson 30-44)一、 单项选择。( )1. Look! She is _ under the tree. A. sit B.siting C. sitting( )2. The girl _ a letter now. A. type B. is typing C. is typeing( )3. There are some _ in the sky. A. clouds B. cloud C.clouds( )4. Now they are _ a bus. A. wait B. waiting C. waiting for