SAT
3/4 of the senior class went to the prom, of which 1/3 brought a date from a different high school. If 38 people at the prom were not from the high school, how many students are there in the senior class?
1. 划分主句和定语从句
2. 确定先行词：“人” 可以从 that，who，whom，whose 中选， “物” 可以从 that，which 中选
3. 把先行词带回定语从句中去，看其在定语从句中做什么语法成分
| 主格 | 宾格 | 定语 | |
| 人 | who，that | whom，who，that | whose |
| 物 | which，that | which，that | whose， of which |
4. 根据先行词“人” / “物”及语法作用确定关系词。有时可以省略，若是作状语的从关系副词 where，when，why 中选，也可介词 + which
一、The girl ________ is reading under the tree is my sister.
1. 先行词为 the girl, 拆分为 The gril is reading under the tree. + The girl is my sister.
2. 先行词放回定语从句中 The gril is reading under the tree，此时 the girl 作从句的主语。
3. 关系词可用 that，who。（ 在树下读书的那个女孩是我的妹妹。）
二、The girl ________ you are waiting for has gone out.
1. 先行词为 the girl，拆分为 You are waiting for a girl. + The girl has gone out.
2. 先行词放回定语从句中 You are waiting for the girl，此时 the girl 作从句的宾语。
3. 关系词可用 whom，who，that。（ 你在等的那个人已经外出了。）
三、This is the university ________ we visited yesterday.
1. 先行词为 the university，拆分为 This is a university. + We visited the university yesterday.
2. 先行词放回定语从句中 We visited the university yesterday，此时 the university 作从句的宾语。
3. 关系词可用 which，that。（ 这就是我们昨天参观了的大学。）
四、This is the university ________ I have learned much knowledge.
1. 先行词为 the university，拆分为 This is a university. + I have learned much knowledge in the university.
2. 先行词放回定语从句中I have learned much knowledge in the university，此时 the university 作从句的状语。
3. 关系词可用 where，in which。（ 这就是让我从中学习了很多知识的大学。）
五、I’ll never forget the days ________ I spent in my university.
1. 先行词为 the days，拆分为 I’ll never forget the days. + I spent the days in my university.
2. 先行词放回定语从句中 I spent the days in my university，此时 the days 作从句的宾语。
3. 关系词可用 which，that。（ 我永远不会忘记那段在大学里的日子。）
六、I’ll never forget the days ________ I stay in my university.
1. 先行词为 the days，拆分为 I’ll never forget the days. + I stay in my university in the days.
2. 先行词放回定语从句中 I stay in my university in the days，此时 the days 作从句的状语。
3. 关系词可用 when，in which。（ 我永远不会忘记那段在大学里的日子。）
七、I live in the room ________ windows faces south.
1. 先行词为 the room，拆分为 I live in the room. + The room’s windows faces south.
2. 先行词放回定语从句中 The room’s windows faces south，此时 the room’s 作windows的定语。
3. 关系词可用 whose。（ 我住在窗户朝南的那间屋子里。）
八、Do you know the reason ________ she was late?
1. 先行词为 the reason，拆分为 Do you know the reason? + For the reason she was late.
2. 先行词放回定语从句中 For the reason she was late，此时 reason 作从句的原因状语。
3. 关系词可用 why。（ 你知道她迟到的原因吗?）
练习
翻译：
geometric sequence 等比数列
A series of numbers in which each is multiplied by a fixed number to produce the next. Like:
