例1：They were government employees(先行词) who(关系词) had been filling out surveys about their health regimens(定语从句). (华慧中国科学院大学阅读真题，2020年)
例2：Our bodies are very good at eliminating all the nasties (先行词) that (关系词) we might digest over the festive season(定语从句). (华慧中国科学院大学阅读真题，2018年)
例3：Their eyes are collecting the surrounding light, which in turn allows them to process and analyze the existing magnetic fields and to keep themselves pointed in the right direction.(华慧吉林大学阅读真题，2015年)
例4：His career began on Wall Street (先行词)almost 70 years ago, where (关系词) he became a pioneer of modern venture capitalism(定语从句), compounding his inherited wealth many times over. (华慧中国科学院大学阅读真题，2011年)
The cat (that) I bought has a cute head. (that 可省)
比较：The cat that is eating an apple has a cute head. (that不可省)
(1)way在定语从句中做状语时的三种引导方式 that / in which / 不填
One final way that men and women differ is in their typical responses to problem-solving. (四川大学阅读真题，2018年)
The way in which / that /不填 he explains the sentence to us is quite simple.
This is the first time that the president has visited the country.
This was the time when there were no radios, no telephones or no TV sets
★此时when = during which 在..期间
(3)先行词reason当在定语从句中作状语时，4中引导方式 why/for which/that/不填
This is the reason why/for which/that/不填 he can not come here.
比较：Is this the reason that/which/不填he explained to us for his absence from the conference.
部分学生看到when, where, why 引导的从句时，倾向于认为时状语从句，其实不然，关系副词也可以引导定语从句，只是在从句中不充当主干成分，而是修饰成分状语。关系副词引导定语从句时，可以替换为：相应的介词+which
(1) when 在定语从句中做时间状语，先行词为表示时间的time, day等
Men’s conversation is peppered with dates and addresses, illustrating their comfort with systems: “Back in 1996 when I was living in Boston…” or “The best way to the new stadium is to go all the way out Walnut Street to 33rd and then get on the bypass…” (四川大学阅读真题，2018年)
（when = in which）
(2) where 在定语从句中做地点状语，先行词为表地点的place, spot等
For example, insects disappear during the cold months, prompting insect-dependent birds to fly south to warm areas where insects breed. (吉林大学阅读真题，2015年)
(where = in which)
(3) why 在定语从句中做原因状语，先行词只有reason.
The reason why she dropped out of school is that she didn’t want to increase the family’s financial burden. (why = for which)