分享几个开头句：
1.Recently the phenomenon has become a heated topic.  最近，这一现象成为了一个热门话题。
2.Recently the problem has been brought into focus.  最近，这个问题引发了关注。
3.Nowadays there is a growing concern over …  现在，人们越来越关注……
4.What calls for special attention is that …  引起特殊关注的是……
5.It is common knowledge that …/It is well-known that …  众所周知……
6.Many nations have been faced with the problem of …  很多国家都面临这……的问题。
7.According to a recent survey …  根据最近的研究……
8.With the rapid development of …  随着……的快速发展。