Change the forms of the following sentences. 句型转换。
1. Is this ball heavy?（加light变为选择疑问句）
2. I like ping-pong best.（同义句转换）
3. I went to the gym today.（对画线部分进行提问）
4. Li Ming arrives at the gym at 7:00.（对画线部分进行提问）
5. I have some work to do. （变为否定句）
1. Is this ball heavy or light?
2. My favourite sport is ping-pong.
3. Where did you go today?
4. When does Li Ming arrive at the gym?
5. I don't have any work to do.