If only I__how to operate a computer as you do.A.had known B.would know C.should know D.knew
问题描述：
If only I__how to operate a computer as you do.
A.had known B.would know C.should know D.knew
答
D
答
yes D
虚拟语气。
答
subjunctive mood
答
D 与现在相反的虚拟语气
答
选D
if only(要是……就好了)用于虚拟语气,与现在相反的假设用过去式
答
knew
答
为什么是b