定语从句的省略用法，关系代词that, which, whom等在限制性定语从句中充当宾语且不位于介词之后时，可以省略。
in which或that在先行词way后作方式状语从句时可省略。
《剑桥雅思真题7》Test 2 Passage 2
But the damage(that/which)it has caused has been colossal.
但它造成的破坏是巨大的。
The man (whom/that) you visited last night is my friend.
你昨晚去拜访的那个人是我的朋友。
I don not like the way (in which/that) you treat the child.
我不喜欢你这样对待孩子。
在限制性定语从句中，当先行词是表时间、地点、原因、方式等的名词时，关系副词when, where, why可以省略。
《剑桥雅思真题9》Test B Section 2
It is suggested that you provide this information early and do not wait until the time(when)you actually meet with the employer.
建议你尽早提供这些信息，不要等到你真正与雇主见面的时候。
The reason(why)he did that is quite clear.
他那么做的理由是非常清楚的。
This is the place(where)I visited last year.
这是我去年到过的地方。
