A.外存
B.主存
C.寄存器组
D.U盘
From the text, we can infer that ______.
A.some computers don't have system software
B.software such as Winword, Excel and Foxpro focus on a single task
C.for a computer to perform a useful task, both the system and application software are inevitable
D.language software helps people to learn a language
以下叙述中正确的是
A.对于逻辑表达式:a++&&b++,设a的值为0,则求解表达式的值后,b的值会发生改变
B.对于逻辑表达式:a++‖b++,设a的值为1,则求解表达式的值后,b的值会发生改变
C.关系运算符的结果有三利1:0,1,-1
D.else不是一条独立的语句,它只是if语句的一部分