If the American government the expert’s suggestion, the world economy would not be in such a mess now.
—How long do you think it will be ________ we win the football World Cup? —Perhaps twenty years.
Silk from China found its way to India, the Middle East and Rome, _______ spices and glass, which was not known to China.
Li Yang, the founder of Crazy English, says that he copies it down _______ he comes to a sentence.
This is the third time I _______ Beijing. The second time I ______ here was on Christmas Day last year.
Computers can do a lot of things nowadays, but _____ more still need to be done by man.