The new traffic rules will become ________ from the first day of 2019.
A. comfortable
B. excellent
C. challenging
D. effective
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下面属于C51合法标识符的是( )。
A. include
B. main
C. PSW
D. R_5
下面语句定义的变量byTemp放置在单片机的( )里面。unsigned char data byTemp;
A. 片内RAM
B. 片外RAM
C. 片内ROM
D. 片外ROM
下面语句定义的变量byTemp能够表示的数值范围是( )。unsigned char data byTemp;
A. -128~+127
B. 0~255
C. -32768~+32767
D. 0~65535
用关键字sbit定义可位寻址的特殊功能寄存器的位寻址变量,下面方法错误的是( )。
A. sbit LED0 = 0x80;
B. sbit LED1 = 0x80^1;
C. sbit LED2 = P0^2;
D. sbit LED3 = P0.3;