"It"作形式主语

　　It is+n.+to do sth./that从句 “(做)某事是...”

　　It is+adj.+(for sb) to do sth./that从句 “(对某人而言)做某事是...的”

　　It is said/reported/well known/estimated+that从句 “据说/据报道/众所周知/据估计...”

　　It is no use/good/worth doing sth./that从句 “做什么是没有用的/不好的/不值得的”

　　(2014年作文—the harm of computer games)

　　It is no good for college students playing computers games.

　　It is harmful for college students to play computer games.

　　It is reported that computer games are now quite popular among college students.

　　"It"作形式宾语

　　主语+find/make/consider/think/feel/believe+it+adj./n.+to do sth./that从句

　　I consider it wrong that many college students are addicted to playing computer games.(2014年作文—the harm of computer games)

　　It is/was+被强调的部分+that/who

　　(被强调部分指人两者都可以使用，指物只能用that)

　　It is computer games that are harmful to students’ health.(2014年作文—the harm of computer games)

　　It is (high/about)+time+that从句

　　(从句谓语：should+V.原/did)、“到了该做某事的时间了”

　　It is high time that the city government should take / took some measures to solve traffic problems.(2024年作文—my suggestions on solving traffic problems)

　　There is no doubt that从句

　　“毫无疑问”

　　There is no doubt that playing computer games is harmful to students’ health.(2014年作文—the harm of computer games)

　　not only...but also...

　　不但...而且...

　　Playing computer games has not only an impact on students’ studies，but it also does harm to their health.(2014年作文—the harm of computer games)

　　倒装：Not only does playing computer games have an impact on students’ studies，but it also does harm to their health.

　　Only in this way+半倒

　　“只有这样”

　　Only in this way will the traffic problems be solved or alleviated.(模拟题—my suggestions on solving traffic problems)

　　so/such...that从句

　　“如此...以至于”

　　Some students get so excited at certain games that they can hardly calm down before bed，which is not good for their sleep.(2014年作文—the harm of computer games)

　　the best way to do sth.“做某事最好的方法是...”

　　The best way to solve the traffic problems is to repair and widen some roads.(2024年作文—my suggestions on solving traffic problems)

　　had better (not) do sth.“最好(不要)做某事”

　　You had better not use smart phones too much because they are bad for your eyes.(2017年作文—addition to smart phones)