I....has both advantages and disadvantages.……既有利又有弊。例如：
1.Obviously television has both advantages and disadvantages.
2.Living in a city has both advantages and disadvantages.
3.Compared with cars，bikes have their advantages and disadvantages.
1.Although computers bring people a lot of convenience，they have many disadvantages.
2....has many advantages.For example，...However，just as every coin has two sides，...has its disadvantages.(本例将利弊分开讲，转折过渡自然。just as every coin has two sides也很值得背诵。)
II....play(s)an important role /part in...……在……中扮演重要角色/起重要作用。例如：
1.Computers play an important role in science and technology.
2.Computers play a more and more important role in our life.
Computers play an increasingly important role in our studies.
3.Education plays an important part in developing our mind.
4.Addiction to alcohol and drugs play a role in homelessness.
1.Advertisement plays an informative role in our daily life.
2.In the past，letters played a decisive role in long-distance
communication.But now ，telephone，email，fax have taken their place.
III.With the development of...，随着……的发展，例如：
1.With the development of our economy，many Chinese families can afford a car.
2.With the development of our economy and society，pollution is more and more serious.
3.With the rapid development of science and technology，people can get a college degree by taking online-courses at home.
4.With the current social and technological developments，employees with more knowledge and higher academic degrees are needed.
1.With the rapid increase of China's population，housing problem is becoming more and more serious. 随着中国人口的急剧增加，住房问题越来越突出。
2.With more and more women entering society，people's attitude towards women is changing.随着越来越多的妇女走入社会，人们对妇女的态度也在改变。
3.With the deepening of Chinese reform and opening up，an increasing number of Chinese
families can afford a car.
随着中国改革开放的深入，越来越多的中国家庭买得起车了。(“越来越多”除了常用的more and more外，还可以用an increasing number of， a growing number of，a significant number of，a great number of等来表达。)
IV.When it comes to...，some people think /believe
that...，others argue /claim that opposite /reverse is true.There is probably
some truth in both arguments /statements，but...当说到……，有些人认为……，但另一些人则持相反的观点……。这两种观点可能都有点道理，但……本结构先用when it comes to ...引出话题，再用some...others ...这个对立的结构引出了两种相反的观点，然后说There is some truth in both...表明严谨公正的态度，最后用but...很自然地引出了自己的论点。请看下面这个例子：
TV，a good thing or bad thing
When it comes to TV，some people believe that it is extremely valuable，as it provides relaxation， entertainment and education. Others argue that it is harmful for it begins to control our lives and deprives people of time to do other activities.There is probably some truth in both sides.But we must realize that television itself is neither good or bad.It is the uses to which it is put that determines its value to society.