【单选题】The frequency of an alternator at a given r/min is determined by the _______ .
A.
number of turns of wire in the armature coil
B.
number of magnetic poles
C.
strength of the magnets used
【单选题】建立文件add.py,写入以下代码: print( “the first number is:”) print(30+50) print(“the second number is:”) 30*50
A.
the first number is: 80 the second number is:
B.
the first number is: 80 the second number is: 150
C.
the first number is: the second number is:
D.
the first number is: 80 the second number is: 150
【单选题】P2口接着8只led,8只led一端接在一起后接入低电平,另一端分别接P2口的一个位输出口,要想使奇位数灯亮,偶位数灯灭,则P2应赋值()
【单选题】There is ____ “u” and _____ “r” in the word “number”.
【单选题】在当前电路中,如果希望8个LED灯由上到下分别是“亮灭亮灭亮灭亮灭”的初始状态,那么在C51代码中,给P1口赋的初始值(十六进制值)应该是多少?
【单选题】设m为无符号字符型变量,m=0x55,则表达式m^0x0f的值为( )
【单选题】程序如下。问数组mtable中的值是多少? #include #define uchar unsigned char #define uint unsigned int //延时 void DelayMS(uint x) { uchar i; while(x--) { for(i=0;i<120;i++); } } //主程序 void main() { //数组的值需要确定 unsigned c...
A.
unsigned char mtable[]={0xff,0x55,0x0,0xff};
B.
unsigned char mtable[]={102,136,0,256};
C.
unsigned char mtable[]={0xAA,0x55,0x0,0xff};
D.
unsigned char mtable[]={0x66,0x99,0x0,0xff};
【单选题】a=0xaa;b=a^0xf0;则b的值为()。