句型转换。 1. I like to play ping-pong. (对划线部
题型：句型转换
问题：
句型转换。
1. I like to play ping-pong. (对划线部分提问)
____________________________ to do?
2. I want to buy clothes in a store. (变一般疑问句)
___________________________________________________________
3. My family likes to have fun together. (对划线部分提问)
___________________________________________________________
4. I go to work by bus. (对划线部分提问)
___________________________________________________________
5. What is your father? (变同义句)
What ___________________ do?
并讨论f(x，y)在(0，0)处是否可微，若可微求出