磁电系电流仪表可以测量()。
A、直流电流
B、交流电流
C、异步电动机的转子电流
D、上述均可
参考答案:A
She treated the boy very well _____he were her own child. [ ]
A. as though
B. unless
C. even though
D. as long as
已知类Myst有一个只需要一个double型参数的构造函数,且将运算符“-”重载为友元函数。要使语句序列( )。 Myst x(3.2),y(5.5),z(0.0); z=8.9-y; y=x-6.3; 能够正常运行,运算符函数operator-应该在类中声明为( )。
A.friend Myst operator-(Myst&,Myst&);
B.friend Myst operator-(Myst,Myst);
C.friend Myst operator-(Myst,Myst&);
D.friend Myst operator-(Myst&,Myst);