下列说法中不正确的是(    )

A．图A中大人提一桶水和两个小孩共同提这桶水静止不动，他们的力对水桶的作用效果相同

B．图B中由甲、乙两图可看出：抽水机能提供水压，电源能提供电压

C．图C中电磁铁吸引大头针的多少反映了电磁铁磁性的强弱

D．图D中的实验装置可以探究灯泡消耗的功率与电流的定量关

句型转换

1. Parents should allow their children to choose their own clothes.(改为被动语态)

    Their children should _____ _____ to choose their own clothes.

2. You should not touch the things on show in the museum.(改为被动语态)

    The things on show _____ _____ _____ in the museum.

3. She spent an hour in finishing reading the comics.(改为同义句)

    It _____ _____ an hour _____ _____ reading the comics.

4. She is a fifteen-year-old.(改为复数句)

    They _____ _____.

5. I didn't go there by bike. I went there on foot.(改为同义句)

    I went there on foot _____ _____ by bike.