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 ...