think back on these three years,many things moved me

问题描述:

think back on these three years,many things moved me
thinking back on these three years,we should give gifts
请问这两句为何一个ing一个原型?

第一句:回想过去的这3年,许多事情让我感动
第二句:当我会想回过去的三年,我们必须感恩
第二句省略了when 是一个进行中的动作,所以用ing