He narrowly escaped _________ in a car accident caused by careless driving.

A．killing

B．to kill

C．being killed

D．to be killed

吗啡作用于延脑极后区阿片受体引起：（）

A．呼吸抑制

B．镇咳作用

C．瞳孔缩小

D．恶心、呕吐

E．外周血管扩张