1、As we all know /as is known to us all.众所周知。
2、Every coin has two sides.任何事都有正反两方面。
3、Just as the saying goes.正像谚语所说。
4、With rapid development of science and technology,more and more people.随着科技的快速发展,越来越多的人。
5、It is common believed that.人们普遍认为。
6、Nowadays there is a growing concern over.最近,引起了人们的关注。
7、It is universally acknowledged that.全世界人都知道。