托福涉及的有关介词的题目重复性很强，而且有规律可循。只要考生善于总结、记忆，还是可以保证得满分的。介词题目主要分布在Written Expression(16-40题)中，出题点主要集中在(1)含有介词的固定短语，(2)含有特定含义的介词误用。
1.含有介词的固定短语：短语或词组中的介词不能随意更换或省略
全真例题分析
(1)Most aquatic animals breathe by means external respiratory organs called gills.
(答案)C 正确的短语为by means of,其中的介词of不能省略
(2) Speed refers only toward the rate of mution without specifying any direction of motion.(94.8)
(答案)A 正确短语形式为refer to
(3) Historical geology deals about data on the development of the Earth gathered from the study of rocks, which are analyzed to determine their age and composition. (93.8)
(答案) A正确短语式式为deal with.
(4)The diamond is the only gemstone composed with just one chemical element, carbon.
(答案) A 正确短语形式为。Be composed of
(5) Best known for his research in statistical mechanics and meson physics. Chen Ning Yang shared the Nobel Prize in 1957 to another physicist from the United States, Tsung-dao Lee.
(答案) C 正确的短语搭配为 share.......with
(6)The doctrine of eminent domain is based the legal tradition that all real property is subject to the control of the state.
(答案) A 正确的短语形式为be based on 其中的介词on不能省掉。
2. 介词用错
解题要点 介词与后面的名词通常有固定的搭配习惯，或有特定的语意功能，不能随意更换。通常，介词毕有含义，不同的介词会使整个句子表达不同的意思。当A、B、C、D四个选择答案中出现单独划线的介词，应首先考虑它是否使用正确。
全真例题分析
(1)Scientists claim that an individual can function from about three days when totally deprived of sleep.
(答案) C from应改用for。表示动作延续的时间应用介词for。
(2) Canadian scarlet-clad guards and mounties with horseback are part of the summer scenery in Ottawa.
(答案) B with改为on,“骑在马背上”应用介词on表示位置。
托福介词的复习主要是针对介词词组的积累和运用，以及介词本身的多种用法。如果能找一些托福介词真题集中练习，相信会对大家很有助益。
