?【15】The demand is that a user _______the operating process carefully before using it.
问题描述：
?【15】The demand is that a user _______the operating process carefully before using it.
A.read B.readsC.has read D. will read
翻译并且分析.
答
A
因为demand 引导的表语从句需要虚拟
虚拟方法是 sb should do 其中should 可以省略 所以选择动词原形