句型转换。

1. This is a white box.(改为一般疑问句) 

_________ _________ a white box?

2. Are you from China?(作肯定回答) 

_________, I _________.

3. His sister is from Kunming.(对画线部分提问)

__________ is his sister ___________?

4. This is a bus.(改为复数句)     

 _________ are __________.

5. She has long legs.(改为同义句)      

_________ legs __________ long.

同一单位工程中，各个分部工程的工程量（或投资）不宜相差太大，每个单位工程中的分部工程数目，不宜少于（）个。

A.3

B.5

C.6

D.7