临床上作为曲精细管受损的指标
A.人绒毛膜促性腺激素B.人胎盘生乳素C.雌激素D.孕激素E.前列腺素
参考答案:B
We want a new music teacher _______ us. [ ]
A. teaching
B. to teach
C. teaches
D. teach
()由内导体、外屏蔽层、绝缘层及外部保护层组成。
A.双绞线
B.卫星线路
C.光缆
D.同轴电缆