小建中汤的功用是（）

A.温中散寒，补气健脾

B.温中补虚，和里缓急

C.沮中补虚，降逆止呕

D.温中补虚，降逆止痛

E.温中做寒，健脾养血

I got close enough to hear them speaking Chinese, and I said "Ni Hao,"just as I________do in China.[    ]

A. must  

B. might  

C. can  

D. should