电源的型式试验包括以下测试:()
A.绝缘阻抗测试
B.接地导通阻抗测试
C.功率测试
D.漏电流测试
参考答案:A, B, D
左心衰竭最早的表现是 ()
A.劳力型呼吸困难
B.咯血
C.肝大
D.水肿
E.发绀
What __________ you supposed __________ when you are in England?[ ]
A. do, to do
B. are, to do
C. are, doing
D. have, to do