第2题:[多选题]A-B-J-007 3 7 4 需要六个晶闸管的可控整流电路有( )。 A. 三相半波 B. 三相全控桥 C. 三相半控桥 D. 三相双反星性 参考答案:BD
第3题:[单选题]In order to protect your private information, you _________choose a combinationthat is easy to remember but unknown to others as your password or PIN. A.had better to B.had better C.have better D.have better to 参考答案:B