气溶胶包括（） A.粉尘、雾和烟 B.气体、烟和蒸气 C.气体、粉尘和烟 D.气体、

Their wages ____by a full third in the past two years.

A had gone down          B would go down 

C have gone down         D goes down

It was several minutes before I was    what was happening.

A．aware

B．concerned

C．awake

D．ashamed

二氧化碳灭火器仅在油脂着火时使用。

桡神经的反射中枢在（）

A.C₃～C₄

B.C₄～C₅

C.C₅～C₆

D.C₆～C₇

E.C₈～T₂

心肌梗死的二级预防不包括（）

A.戒烟

B.降脂

C.阿司匹林

D.ACEI

E.短效钙拮抗剂