导体中电流的流动方向为()的流动方向
A、正电荷
B、负电荷
C、中子
D、电子
参考答案:A
The teacher said the earth ________ around the sun. [ ]
A. go
B. goes
C. went
D. going
下列程序的输出结果是( )
#include<stdio.h>
main()
int a=3,b=2,c=1;
if(a<b)
if(b<0) c=0;
else c++;
printf("%d\n",c);
A) 0 B) 2 C) 1 D) 3