Not until my mother came back_________ go to bed.

Nowadays, more and more people would rather ______ in the country, because there is ______ pollution than in the city.

When ________ you have a school trip Sorry, I ________ know.

December 17, 2011 was a sad day for the North Koreans, ______ their top leader Kim Jung-ill passed away unexpectedly

“Perhaps we need to send for DrSmith to see what we can do about it,” Fathersuggested________to his neighbor who had come to discuss the problem [ ]