女性不孕的最常见原因是（）
A.子宫颈因素
B.子宫因素
C.输卵管因素
D.外阴、 * * 因素
E.排卵障碍
参考答案：C
办公楼内的厕所距离最远的工作点不应大于( )m。
A．30 B．50 C．80 D．100
The senior senator has in the past three terms both experienced the sweet taste of success and the bitterness of defeat in his legislation fights with his opponents.
A．both experiences
B．experiences both
C．experience both
D．experienced both
