1 Never in our history has the idea that ... been so popular.

2 Faced with ..., quite a few people argue that ...

3 It is high time that strict measures were taken to stop ...

4 It is necessary that steps should be taken to ...

5 Many nations have been faced with the problem of ...

6 Recently the problem has been brought into focus.

7 Recently the phenomenon has become a heated topic.

8 According to a recent survey, ...

9 With the rapid development of ..., ...

10 From what has been discussed above, we can draw the conclusion that ...