最早合成的苯二氮类药物为()
A．劳拉西泮
B．氯氮卓
C．咪达唑仑
D．硝基安定
E．去甲羟安定
参考答案：B
Don't scold him; even an experienced engineer _____ make such a mistake after all.
A．must
B．can
C．should
D．dare
