句型转换，每空一词。

1.The man has to see a doctor. (改为否定句)

   The man ______ _____  to see a doctor.

2.They are staying there for three weeks.(对划线部分提问) 

   _____ _____ are they staying there?

3. Tom is 10 years old. Bob is 12 years old. (合并为一句)

     Tom is two years _____ _____  Bob.

4. Shanghai is the biggest city in China.(改为同义句)

    Shanghai is bigger than _____ _____ _____  in China.

5. Mary needs to take a bus to school.(改为一般疑问句)

   _____ Mary_____  to take a bus to school?