变压器有载分接开关主要由哪些部件组成？
参考答案：
a、切换开关b、选择开关c、范围开关d、操作机构和快速机构等
______ you may have , you should gather your courage to face the challenge .
A．However serious a problem
B．Whatever serious a problem
C．However a serious problem
D．No matter how a serious problem
反映内皮细胞受损的指标有（）
A.vWF降低
B.血小板降低
C.内皮素生成降低
D.束臂实验阳性
E.6-酮-PGF1α降低
