1.An advantage of ~~~ is that + 句子 (...的优点是...)
例句：An advantage of using the solar energy is that it won't create (produce) any pollution.
2.So + 形容词 + be + 主词 + that + 句子 (如此...以致于...)
例句：So precious is time that we can't afford to waste it.
3.It is universally acknowledged that + 句子~~ (全世界都知道...)
例句：It is universally acknowledged that trees are indispensable to us.
1)It has more disadvantages than advantages.
2)It does us much harm.
3)It is harmfulto us.
例如：However,everything dividesinto two.Television can also be harmful to us.It can do harm to our health and make us lazy if we spend too much time watching televi- sion.
1)There are three reasons for this.
2)The reasons for this are as follows.
3)The reason for this is obvious.
4)The reason for this is not far to seek.
5)The reason for this is that...
例如： There are three reasons for the changes that have taken place in our life.Firstly,peoples living standard has been greatly improved.Secondly,most people are well paid,and they can afford what they need or like.Last but not least,more and more people prefer to enjoy modern life.
1)It is important(necessary,difficult,convenient,possible)for sb.to do sth.
2)We think it necessary to do sth.
3)It plays an important role in our life.
例如： Computers are now being used everywhere,whether in the government,in schools or in business.Soon,computers will be found in every home,too.We have good reason to say that computers are playing an increasingly important role in our life and we have stepped into the Computer Age.
7.、There is no denying that + S + V ...(不可否认的...)
例句：There is no denying that the qualities of our living have gone from bad to worse.
1)We should take some effective measures.
2)We should try our best to overcome(conquer)the difficulties.
3)We should do our utmost in doing sth.
4)We should solve the problems that we are confronted(faced)with.
例如：The housing problem that we are confronted with is becoming more and more serious.Therefore,we must take some effective measures to solve it.