吗啡的药理作用有()
A.镇痛
B.镇静
C.镇咳
D.止吐
E.止泻
参考答案:A, B, C, E
__________along the quiet road at forty miles an hour,and then an old man suddenly started to cross the road in front of me.
A.Driving
B.I was driving
C.Having driven
D.When I was driving
曳引驱动使传动机构体积大大增加。