请问“during/for/in”三者的不同用法.
问题描述：
请问“during/for/in”三者的不同用法.
如题.
答
for 加一段时间：某一动作或状态持续了多久：He has worked here for the last three years.during 和in 有时可通用,指的是在某一段时间期间,如：He has been here many times in / during the last three years....