血友病甲是缺乏凝血因子()
A．Ⅺ
B．Ⅷ
C．Ⅸ
D．Ⅶ
E．Ⅴ
参考答案：B
_________ she milk cows last Sunday?[ ]
A. Did
B. Does
C. Do
血液直接回流到下腔静脉的器官是 ( )
A．胃
B．脾
C．空肠
D．肾
E．胆囊
