七)開篇
    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 ..., ...