It was five o’clock in the afternoon       they arrived at the hotel

A．since    B．before    C．that D when

四神丸中“姜枣同煮，枣肉为丸”的用意是（）。

A.调和营卫

B.温补脾胃

C.补中养血

D.调和诸药

E.温中止泻