可治疗神经源性尿崩症的抗癫痫药是
A．丙戊酸钠
B．卡马西平
C．苯妥英钠
D．苯巴比妥
E．氯硝西泮
参考答案：B
He opened the envelop, had it_____ and began to read it.
A．unfolding
B．folding
C．unfolded
D．folded
粗车时为了提高生产效率，选用切削用量时，应首先取较大的（）
