发热，汗自出、时时恶风、心烦、口燥渴、脉洪大，治用：（）

A.竹叶石膏汤

B.栀子豉汤

C.白虎汤

D.桂枝汤

E.白虎加人参汤

To have a computer without being connected to the Web is like having an old radio when everybody else has a color TV. That helps explain ______ businesses are setting up Net sites even though profits are nowhere to see.

A．reasons

B．the reason for

C．why

D．why that