---- __________is the train station from this shopping mall, do you know?

---- About 30 minutes by bus.

A．How much

B．How long

C．How far

D．How soon

房改促进了住房市场的发育，市场机制已在有效地调节住房的( )。

A．供应

B．需求

C．紧张程度

D．供应和需求