______ it rain tomorrow, we would have to put off the visit to the Water Cube.

A．Should

B．Could

C．Had

D．Were

句型转换。

1. The weather is so cold that we can't go out. (改为同义句) 　　　

    The weather is ____ cold for us ___ out. 　　

2. May I come in? (改为同义句) 　　　

    ___ I come in? 　　

3. The bus stop is three kilometers form the hotel. (对划线部分提问) 　　　

    ___ ___ ___ the bus stop form the hotel? 　　

4. I can speak some English. (改为否定句) 　　　

    I ___ speak ___ English. 　　

5. You are so young. You can't go to Beijing. (合并成一个句子) 　　　 

    ____________________________________________.