凝血酶原时间正常见于（）
A.维生素K缺乏
B.慢性肝病肝功能失代偿
C.血友病
D.口服双香豆素
E.先天性Ⅴ因子缺乏
参考答案：C
— Good evening. Bell Tower Hotel.
— Good evening. ________?
A．What would you like, please
B．Do you still have a room for tonight
C．Is there anything I can do for you
D．Who is that speaking, please
YJ17卷烟机上下两个磨刀砂轮分别由两个（）带动。
A.齿轮
B.带轮
C.齿轮轴
D.电机
