精选优质文档-倾情为你奉上一、引出开头1：It is well-known to us that（我们都知道）=As far as my knowledge is concerned, （ 就我所知）2：Recently the problem of has been brought into focus. =Nowadays there is a growing concern over （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 our day-to-day life. It has brought a lot of benefits but has created some serious problems as well.（互联网已在我们的生活扮演着越来越重要的角
