1600kVA以下三相变压器,各相直流电阻测得值的相互差值应小于平均值的()。
A.1%
B.2%
C.3%
D.4%
参考答案:D
Chinese Premier Wen Jiabao _____ open the 2010 Asian Games in the middle of the Pearl River on
Haixinsha Island. [ ]
A. published
B. declared
C. announced
D. called
有A1、A2两元素。已知A2原子中L层电子数是M层电子数的4/7,而A1原子中M层电子数是A2原子中M层电子数的1/2。A1、A2分别是( )
A.Cl、F
B.Fe、Cl
C.Br、Al
D.Al、Br