句型转换。

1. My grandpa listens to the radio every day. (用at this time yesterday改写)

    My grandpa _____  _____ to the radio at this time yesterday.

2. Let's go and have a look, _____  _____? (改为反意疑问句)

3. I borrowed an MP4 from Kate yesterday. (改为同义句)

    Kate _____ an MP4 _____ me yesterday.

4. Mr. Wang is very busy. He can't go fishing with my father. (改为同义句)

    Mr. Wang is _____ busy _____ go fishing with my father.

5. They were climbing the mountain when it began to rain. (就划线部分提问)

    What _____ they _____ when it began to rain?

为了测定某额定功率为1000W的电热水器的效率，物理兴趣小组的同学在热水器中加了2kg的水，让热水器正常工作，并绘制出通电加热过程中水温随时间的变化情况图，求：  

（1）加热2min，水的温度升高了多少摄氏度？ 

（2）加热6min，水吸收了多少热量？  

（3）电热水器的效率是指水吸收的热量与电热水器放出的热量之比，该热水器正常工作时的效率为多少？