发生受精时，精子不通过的结构是（）
A.放射冠
B.透明带
C.卵黄膜
D.卵黄周隙
E.卵巢鞘膜
参考答案：E
关于强直性脊柱炎错误的是
A．常出现脊柱侧弯畸形
B．HLA-B27阳性率高
C．早期常累及双侧骶髂关节
D．可累积髋关节，导致关节僵直
E．多见于年轻，女性
____ they all have in common is that they combine fun _____ the opportunity to learn something.
[ ]
A. What; with
B. What; on
C. Which; with
D. Who; for
