隔离开关是高压电器中应用较少的一种电器
参考答案：错
He was crazy ____ the girl, but it was crazy ____ him to let such a young girl drive his car.
A．about ; of
B．with ;of
C．to; of
D．about; for
关于正常的脐带结构描述正确的是（）。
A.一条动脉，一条静脉
B.一条动脉，二条静脉
C.二条动脉，一条静脉
D.静脉较粗，壁厚
E.动脉较细，壁薄
