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色，它给我们带来了许多好处但也产生了一些严重的问题。