当测定石油沥青的针人度为25时,其沥青标号为______号。
A.20
B.25
C.30
D.40
参考答案:C
下面程序的运行结果是( )。 #included<iostream.h> class base protected: int a; public: base()cout<<"0"; ; class base1:virtual base public: base1()cout<<"1"; ; class base2:virtual base public: base2()cout<<"2"; ; class derived:public base1,public base2 public: derived()cout<<"3"; ; void main() derived obj; cout<<endl;
A.0123
B.3120
C.0312
D.3012
逆变器类型分布式电源接入220/380伏配电网,其接入容量超过本台区配变额定容量()时,配变低压侧刀熔总开关应改造为低压总开关,并在配变低压母线处装设反孤岛装置
A、0.2
B、0.25
C、0.3
D、0.5