1. 句型转换

1. （1） To save energy is important for our daily life. (改为同义句)

   important energy for our daily life.

3. （2） You mustn't throw about the paper anywhere. (改为同义句)

   the paper anywhere.

5. （3） He came into the room. His father was watching TV. (用while合并为一句)

7. （4） We are careful about the traffic on the road. We are safe. (改为含有if引导的复合句)