1.Mary went to the park last Saturday.(改成一般疑问句,并作否定回答）
Did Mary go to the park last Saturday
No,She didn't.
2.He (drank a lot of milk) when he was ill.（对括号部分进行提问）
What did he do when he was ill
3.Liu Wei sang and danced on his birthday (at home).（对括号部分进行提问）
Where did Liu Wei sing and dance on his birthday
4.I watch TV the day before yesterday afternoon.(改为否定句）
I did n't watch TV the day before yesterday afternoon.
5.He didn't answer my question.（改为一般疑问句）
Did he answer your question
6.She was very sad at the news.(改为一般疑问句）
Was hse very sad at the news
不明白的再问哟,请及时采纳,多谢!