1) It is advisable to exercise(拥有) patience in dealing with such complicated situations。
遇到这类复杂的情况，明智的做法是要有耐性。
这句里，It代指“to exercise(拥有) patience”，后面的“in……”作状语，为“在……中”
以下同理(红色字体为主语部分，也就是it代指内容)
2) It is advisable to place important telephone numbers next to the phone in case of an emergency.
建议把重要的电话号码放在电话机旁，以备出现紧急情况。
3) It is biologically reasonable for deer to reduce their cost of living to increase their chances of surviving in winter.
为了提高冬季存活的机率，鹿必须明智的从生理上减少生存成本.
此外，it is\was……that也是高频句式
4) It is essential that the increase in production should be geared to (适应) the increase in public demand.
生产量的提高必须和大众的需求相适应。
此句中，it代指的即为that后面成分，这种句式被称为“主语从句”。再如下面三句：
5) It is necessary that young and old people should communicate more with each other。
年轻人和老人应该多多沟通是很有必要的。
6) It is incredible(不可思议) that he ate the big cake just in two bites.
不可思议的是，他两口就解决了那个大蛋糕，
7) It is certain that fresh air and exercises are more valuable than medicine。
新鲜的空气和锻炼比药更有用
试着学习这些句子吧！
8) It is certain that with determination and hard work you will succeed eventually。
下定决心，努力工作，你肯定会成功。
9) It is easy to fall into bad habits but very difficult to break away form them。
养成坏习惯很容易，而摆脱却很难。
10) It was not until about 1600B.C. when the chariot (马拉战车) was invented that the maximum speed was raised to roughly twenty miles per hour.
直到公元前1600年，马拉战车才被发明出来，最高速度提升到大概每小时20英里。
11) It was in times of crisis that I finally found out what he was really like。
就是在危难时刻，我才终于发现他到底是个什么样的人。
12) It takes (took) sb. some time to do sth。
某人花费多长时间去做某事
13) It can be argued that such a response may not mean much (有人认为……)
14) It is reported that the electronic industry is going on rapidly in recent year。
15) It pays in the long run (从长远的角度看……) to introduce new technique
16) It has been only twenty-five years since television came to one of people’s pastimes。作者: kobe 时间: 2010-10-18 18:45
