急性心力衰竭的病因有（）。
A.精神紧张
B.高血压急症
C.输液过多、过快
D.严重心律失常
E.急性广泛心肌梗死
参考答案：B, C, D, E
— Excuse me, do you have the time?
— _____. [ ]
A. Of course, I have
B. No problem
C. Yes, I do
D. A quarter to ten
可保留的牙齿其牙槽骨吸收不能超过根长的（）
A.1/4
B.1/3
C.2/3
D.1/5
E.1/2
