30. The No. 5 subway line, ______in October, 2007, has greatly improved the traffic conditions in Beijing.
There is no____ that China will be a powerful country in the future.
―I’m too tired. I want to give up. ― If you don’t ________, you’ll win in the end.
---What did the Englishman say? ---Oh, he asked where ____ .
The number of the students in our school ____ rising since 2006.
Helen has had a lot of trouble these days,but she doesn’t know whom to ______ for help.