牛津7A Unit 8 Grammar(14)

将下列句子改为否定句 1. I am teaching English. 2. My mother is making cakes. 3. The students are chatting in the class.写出下列句子的疑问形式并做肯定及否定回答：

I am doing my homework now. Sandy is flying a kite right now. They are chatting with each other.