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 ..., ...