根据句意，用括号内所给单词的适当形式填空。

1. Would you mind  _____ (teach) me English?

2. Shall I  ____ (clean)the door now, mom?

3. Many students teach _____ (them)on the Internet now.

4. David Beckham is my favorite _____ (play).

5. _____ (take)good care of the baby is his duty.

6. She mustn't _____ (stay)up too late.

7. Do we need _____ (bring)the raincoat with us?

8. One of our classmates _____ (come)from Hunan.

9. Do you have fun _____ (study)English?

10. Michael spends two hours _____ (exercise)every day.

进行线性盈亏平衡分析时，（）是固定成本。

A．不随利息变化而变化的成本

B．不随盈利变化而变化的成本

C．不随税金变化而变化的成本

D．不随产量变化而变化的成本