特权指令只能在内核态下执行,而不能在用户态下执行。
参考答案:对
解析:特权指令可以访问计算机的所有资源,它的执行只能在内核态下。
___ no need for us to discuss the problem again. It has already been settled.
A.It has
B.There has
C.It is
D.There is
简述当代主要的教学理论流派。