新航道上海学校SAT培训班小编继续给大家带来SAT文法第八期，每期分享3-5个文法知识点，帮助大家更好地备考SAT。

  一、代词

  (四)关系代词

  1. 含义：

  主从句中引导从句的关系代词，起到连接主从句作用，并作一定的句子成分。

  2. 用法：

  (1)who指代人，作主语。

  例如：

  Tom is a student who studies SAT.(who指代主句的a student，在从句中作主语。)

  (2)whose指代人，意思是“谁的”，相当于形容词，后加名词一起作主语。

  例如：

  There are two books. Whose book is this?(whose+book作从句的主语。)

  (3)whom指代人，作宾语。

  例如：

  The company hired two graduates, both of whom are from China.(both of whom指代graduates，whom在介词of之后，在从句中作宾语。)

  (4)which指代物，作主语。

  例如：

  Qingdao is the place which has issued a red rainstorm warning.(which指代主句的the place，在从句中作主语。)

  (5)that指代人或物，作主语或宾语。

  例如：

  Mary bought a hat that is fashionable.(that指代主句的a hat，在从句中作主语)

  真题检测

  真题检测1

  (2021-03AS-Q29) Changes in air temperature caused wind pattern to shift, that shift in turn triggered a process known as upwelling.

  A. NO CHANGE

  B. this

  C. which

  D. DELETE the underlined portion.

  解析：通过that等选项看出是关系代词的考点，根据which指代物和that前不加逗号的规则，同时this和DELETE选项句子结构不完整。所以排除A/B/D三个选项，所以选C。

  注：2021-03AS-Q29为2021年3月亚太真题29题。

  真题检测2

  (2016-05NA-Q4) The plastic harden quickly, it allows the printer to build the layers of the final model

  A. NO CHANGE

  B. this

  C. which

  D. that

  解析：通过that等选项看出是关系代词的考点，根据which指代物和that前不加逗号的规则，同时this和it选项句子结构不完整。所以排除A/B/D三个选项，所以选C。

  注：2016-05NA-Q4为2015年5月北美真题4题。

  真题检测3

  (2016-05NA-Q14) These political machines were able to pack legislatures and courts with hand-picked supporters by purchasing votes, a form of election fraud involving the exchange of money or favors for votes.

  A. NO CHANGE

  B. votes, being

  C. votes, that is

  D. votes, which it is

  解析：通过that等选项看出是关系代词的考点，原文逗号后面内容为解释说明购票的这种行为，所以无需加任何修饰。B项being表述啰嗦，C项that前不能加逗号，而D项的it多余，所以排除B/C/D三个选项，所以选A。

  注：2016-05NA-Q14为2015年5月北美真题14题。

  真题检测4

  (2016-11AS-Q13) Contrary to the traditional view of evolution, holding that evolution stops in an unchanging environment, Lenski had predicted that the bacteria would evolve, or mutate, over time.

  A. NO CHANGE

  B. which holds

  C. this holds

  D. it holds

  解析：通过that等选项看出是关系代词的考点，holding that evolution插入语部分是修饰traditional view of evolution，所以用定语从句更为合适，A项holding语法上可以是Lenski发出，句意错误;C和D项是run-on错误(即逗号不能单独连接两个独立句)，所以排除A/C/D三个选项，所以选B。

  注：2016-11AS-Q13为2016年11月亚太真题13题。

  真题检测5

  (2017-01NA-Q16) The lion dance requires the strength, grace, and coordination of two dancers, both of whom are almost completely hidden by the elaborate bamboo and papier-mache lion costume that they maneuver.

  A. NO CHANGE

  B. it

  C. these

  D. that

  解析：通过that等选项看出是关系代词的考点，both of whom指代two dancers，所以用定语从句更为合适，B项的it、C项的these和D项的that都是run-on错误，所以排除B/C/D三个选项，所以选A。

  注：2017-01NA-Q16为2017年1月北美真题16题。