In the past few years, so many areas throughout the world have been hit by such destructive earthquakes, snowstorms and tsunamis ______ we have never experienced before, ______ makes us worried a lot about nature disasters.

A. A. that; that      B. as; which         C. which; it        D. when; as

常见的给药差错有（）

A.给错药物

B.给错患者

C.给错剂量

D.给错用药途径

E.给错时间