句型转换。

1. This is my father. (改为一般疑问句)

    _____ this _____ father?

2. My basketballs are in the box. (改为否定句)

    My basketballs _____ _____ in the box.

3. Mary's pencil is yellow. (对画线部分提问)

    _____ _____ is Mary's pencil?

4. I have a big sports collection.(改为一般疑问句) 

    _____ you _____ a big sports collection?

5. This is a ruler. (改为复数句)

    _____ are _____ .

因负荷过大输送机启动不起来要及时停车，连续启动不超过（）次，每次启动时间不得超过（）