—Why does Joe look so _______ today?

—Because she has got an "A" in her English test. [ ]

A. exciting

B. sad

C. happy

D. angry

某药半衰期为5小时，一次静脉注射后，从体内基本消除需（）。

A.10小时左右

B.15小时左右

C.1天左右

D.2天左右

E.3天左右