精索静脉丛在何处汇合成精索内静脉
A.腹膜后
B.盆腔
C.腹股沟管内环
D.腹股沟管外环
参考答案:C
This is _____ English dictionary. That's Chinese dictionary. [ ]
A. an, a
B. an, an
C. a, an
D. a, a
刚性联轴器分哪两种?