沿斜面匀速下滑的物体如图所示，受到的作用力有

A．重力、支持力

B．重力、支持力、摩擦力

C．重力、支持力、下滑力、摩擦力

D．重力、压力、下滑力、摩擦力

句型转换。

1. I have a cold. (就画线部分提问)

                                          you?

2. My father does exercise every morning. (用be going to改写句子)

    My father is             ______ exercise tomorrow morning.

3. They have to get up early every day. (改为一般疑问句)

    _____they _____ _____ get up early every day?

4. Lucy got to Beijing yesterday. ( 改为同义句)

    Lucy             Beijing yesterday.

5. There will be a school sports meet next week. (改为否定句)

               a school sports meet next week.