35岁以上的高龄产妇，分娩唐氏综合征胎儿的概率为
A．0.5E
B．1E
C．2E
D．2.5E
E．3E
参考答案：B
肺栓塞肝素应用的禁忌证：______，______，______，______，______，______。
—____ do you go home to see your parents ?
— Twice a month.
A．How often
B．How long
C．How far
D．How old
