主语从句：it is …

　　It is important/vital/crucial/pivotal/essential/significant(…很重要)

　　It is clear/evident/obvious/manifest/as clear as crystal/quite common(…很明显)

　　It is undoubted/undeniable/doubtless (…毋庸置疑)

　　It is a pity/a shame/a common sense/practice(…这是个常识)

　　It is well/increasingly/widely/commonly/generally known/recognized/accepted/acknowledged(众所周知)

　　It is conceivable that 可想而知

　　It is desirable/admirable that 可取的

　　It is advisable that 最好做某事

　　It is probable/possible/likely that 可能的

　　It is imperative that 必要的

　　it is preferable/profitable that

　　It is hazardous/risky/perilous that 危险的

　　It must be stressed out that 必须要指出

　　It must be admitted that 必须要承认

　　It is reported that 据报道

　　It is suggested that 有人建议

　　It is assumed that 有人认为

　　It is estimated that 据估计

　　It is always the case that 情况总是这样的

　　It is not always the case that 情况不一定总是这样的

　　It follows that由此可见，

　　表语从句：is

　　我的第一个理由是，学术课程经历了时间的考验而且代表了古老文化的精华。

　　My first reason is that academic courses withstand the test of time and represent the essence of ancient cultures.

　　在教育中使用电脑的一个优点是，他们能够最大程度上丰富传统的教学方法。

　　One advantage of the application of computers in education is that they can enrich the traditional teaching methods to a great extent.

　　同位语从句：

　　常用的：the fact/idea/belief/recognition/suggestion/proposal/attempt/effort that

　　Be based on the belief that 基于这样的想法

　　From the above discussion, we can safely draw the conclusion that…

　　There is no evidence that…

　　Despite the fact that….

　　neglect/ignore/overlook/ lose sight of / be blind to/fail to consider the fact that忽视了某个事实

　　政府不应该忽视这样的事实，囚禁罪犯最起码是对受害者的安慰。

　　The government should not be blind to the fact that imprisonment of criminals is the comfort to the victims at the very least.

　　大学生应该承担全部学费，基于这样的一种普遍认识，那就是，大学生通常比没有学位的人赚钱多很多。

　　University students should bear total expenses for their tuition on the generalization that university students usually earn much more than people without a degree.

　　定语从句：

　　定语从句：名词(短定语)人，who,物，which, that…

　　Those who+谓语

　　支持这种观点的人给出如下理由。

　　Those who favor this view give the following reasons.

　　上网成瘾的人总是会孤立的，不善于社交的，甚至是抑郁的。

　　Those who are addicted to the Internet tend to be isolated, unsociable or even depressed.