One of the requirements for a fire is that the material _________ to its burning temperature.
Chinese exports have been hit hard by falling world demand, with millions of workers _______ to their villages after the factories that employed them closed down.
There would be not a good harvest of wheat in North China this year _______ the big snow.
Yao Ming, a NBA superstar, became the boss of Shanghai basketball team, and is ready to _______ in new world of basketball.
-- Director Wang, a man is waiting to see you outside, _______ he come in?-- In a moment. I' m busy right now.
Li Yang, the founder of Crazy English, says that he copies it down _______ he comes to a sentence.