句型转换。

1. My favourite sport is tennis. (对画线部分提问) 

                                  favourite sport?

2. watch,the, zoo, the, to, you, do, like, to, go, to, animals  (连词成句)  

                                                          ?

3. Daming usually gets to school at 7 o'clock. (对画线部分提问)  

                                 Daming usually get to school?

4. English is difficult. Maths is more difficult. (合并成一句) 

    Maths is                                             English.

5. You get up later than me. (改为同义句)

    I get up                than you.

当三相负载不平衡时，在零线上出现零序电流，零线对地呈现电压，可能导致触电事故。