提升钢丝绳在滚筒上缠绕时，与已在滚筒上的绳圈相不显，挤压或摩擦的现象称作（）。

A.滑动

B.蠕动

C.咬绳

句型转换。

1. There are some CDs and hair clips on the desk. (改为一般疑问句)

             there            CDs or hair clips on the desk?

2. My uncle does housework at home. (否定句)

    My uncle                       housework at home.

3. There are two policemen at the gate. (对画线部分提问)

                         policemen are there at the gate?

4. She runs with her dog for half an hour on Saturday. (对画线部分提问)

                          does she run with her dog on Saturday?

5. She is in the Swimming Club. (改为同义句)

    She is a _____ _____ the Swimming Club．