介绍性短语

introductory course───基础入门课程

introductoriness───导言

introductory───adj.引导的，介绍的；开端的

introductorily───介绍

introduce a character───介绍一个人物

infinitive phrase───不定式短语

introduce a policy───介绍政策

If the introductory phrase of your sentence cannot sensibly modify the subject, consider clarifying your sentence by replacing the subject.───如果句子的介绍性词组不能明确修饰主语，可替换主语，以明确句意。

This suggested revision reduces the word count to 20 from 27. It does so by shortening one introductory phrase and eliminating a second.───句子照建议修改，缩短第一个片语、删除第二个片语后，字数从27个字减少到20个字。