复合句是TOEEL考题的基本句子结构，因而连接主句和从句的连接词就成为重要的命题焦点。TOEEL常考的从属连词分三类：（1）关系代词( that, which ,what who. Whose) (2) 关系副词（where when why how) (3) 状语从句连接词 (where, when, if, though, because…) 有关从属连词的试题大部分集中在Structure (1-15题中) 掌握命题规律，这类题目并不复杂。从属连词常考题型及解题要点
(1)The spiral threads of a spider*s web have a sticky substance on them ------- insects.
(B) trap its
(C) which traps
(D) which it traps (92.1)
[答案] C 定语从句关系代词which引导从句，且在从句中作主语。
(2)Angiosperms inhabit relatively diverse environments and may be found ------- higher plants can survive.
(D) then (92.5)
[答案] B 空格前后为两个完整的句子，这里应填入连接词联系主从两句。四个选择只有wherever是连词，引导地点状语从句。
(3)Duke Wellington was a composer. Conductor, and pianist ------ ranked as one of the greatest of all jazz figures.
(D) who (92.10)
[答案] D 关系代词who引导定语从句，并作从句的主语。
(4)-------. Some of the Earth*s interior heat escapes to the surface.
(A) A volcano erupts
(B) A volcano whether erupts
(C) A volcano erupts it
(D) If a volcano erupts (93.5)
[答案] D 从属连词引导条件状语从句。
2. 关系代词 who与which混淆错用
解题要点：在written Expression (16-40题）中的四个选择答案中出现who 或者which，应确认它所指代的是人还是物。
(1)Fossil remains indicate that squidlike creatures called belemnites swam in the sea who covered the North American continent 70 million years ago. (94.5)
[答案] C 关系代词who指代的是sea，因此应用指物的which或that。
(2)Vaccines for some rare diseases are given only to persons which risk exposure to the disease. (93.1)
[答案] B 关系代词which指代前面的persons，应改为人称关系代词who。
(3)Anne Elizabeth McDowell is best remembered for a weekly journal, the Woman*s Advocate, who she launched in January 1855. (91.8)
[答案] D 关系代词who指代杂志the woman*s Advocate,故应改为which。
(4) The attorney general of the United States advises the President on any questions of law who may arise in the conduct of administrative affairs. (90.10)
[答案] B 关系代词who指代前文的questions of law，故应改为which或that。
解题要点 介词＋which作用相当于一个关系副词，在从句作状语。可表示时间（＝when) ,地点(= where) ，原因（＝why）等等。
(1) In reorganizing the curriculum of Mt. Holyoke College in the late 1800*s Elizabeth Mead laid the foundation ------- the modern college rests.
(A) is which
(B) on which
(C) which is on
(D) on it (91.1)
[答案] B on which 指代on the foundation ，作用相当于一个表示地点的关系副词。
(2) A circuit may be defined as a closed path ------- electricity can How.
(A) through it
(B) through which
(C) that is through
(D) there goes through (93.3)
[答案] B through which 指代through the circuit, 作用相当于一个关系副词，而介词through才能准确地表达句子的含义。
(3) The extent of the harmful effect of locoweeds on animals depends on the soil ------- the plants grow.
(B) which in
(C) in which
(D) in (90.5)
[答案] C in which = where
(4) Adhesives, such as glue, tape and gum, vary with the purpose ------- intended.
(A) they were for
(B) for they were
(C) which were they
(D) for which they were (93.10)
[答案] D for which指代for the purpose。