直流母线的负极相色漆规定是涂为()色。
A、黑
B、白
C、蓝
参考答案:C
____I think she is a good singer.
____ ________.I haven't heard a better voice.
A.Absolutely
B.All right
C.The more, the better
D.Who said it
慢性脓胸肺内无病变者,理想的治疗方法是()。
A.胸腔闭式引流术
B.开窗引流术
C.胸膜纤维板剥脱术
D.胸廓成形术
E.胸膜肺切除术