为了使74LS138译码器6端(Y6')输出为低电平,输入端A2A1A0应置成
A. 110
B. 011
C. 101
D. 111
在登录你的电子信箱的过程中,要有两个条件,一个是用户名,一个是与用户名对应的密码,要完成这个事件(登录成功),它们体现的逻辑关系为
A. 或
B. 非
C. 与
D. 无逻辑关系
In the exam, theyou are, themistakes you will make.
A. careful; little
B. more careful; fewest
C. more careful; fewer
D. more careful; less
I hurried I wasn' t late for class.
A. since
B. so that
C. as if
D. unless