七)开篇
1) many nations have been faced with the problem of ...
2) recently the problem has been brought into focus.
3) recently the phenomenon has become a heated topic.
4) recently the issue has aroused great concern among ...
5) nowadays there is a growing concern over ...
6) never in our history has the idea that ... been so popular.
7) faced with ..., quite a few people argue that ...
8) according to a recent survey, ...
9) with the rapid development of ..., ...