As we know, England is ______ European country and Singapore is ______Asian country.

A．an; an

B．an; a

C．a; a

D．a; an

新架设的母线与带电母线邻近或平行时应（）。

A.制定防护措施

B.接地

C.加装绝缘套

D.采取防静电措施