句型转换。

1. I eat sandwich today. (用yesterday替换today) 

    I ________ sandwich ________. 

2. I am doing my homework. (改成一般疑问句)

    ________ you doing ________ homework?  

3. Li Ming saw Danny yesterday. (改成否定句)

    Li Ming ________ ________ Danny yesterday.  

4. They went to Beijing by train last Sunday. (对划线部分提问) 

     ________ ________ they ________ to Beijing last Sunday?

5. Danny bought this hat for Kim. (对划线部分提问)   

   What did Danny ________ for Kim?