1：It is well-known to us that……（我们都知道……）==As far as myknowledge is concerned, …（就我所知…）
2：Recently the problem of…… has been brought into focus. ==Nowadays there is a growing concernover ……（最近……问题引起了关注）
3：Nowadays（overpopulation）has become a problem we have to face.（现今，人口过剩已成为我们不得不面对的问题）
4：Internet has been playing an increasingly important role in ourday-to-day life. It has brought a lot of benefits but has created some serious problems aswell.（互联网已在我们的生活扮演着越来越重要的角色，它给我们带来了许多好处但也产生了一些严重的问题）
5：With the rapid development of science and technology，more and morepeople believe that……（随着科技的迅速发展，越来越多的人认为…
6：It is a common belief that……==It is commonlybelieved that……（人们一般认为……）