. Knowledge of English is a must in international trade.
Once new difficulties _____ in our study, we should learn to use our brains to solve them.
— Sorry, Ann. I’m afraid that I can’t go to the magic show by David Copperfield with you. —____. Who knows when he will be back here next time?
_____ Chinese basketball player Yao Ming will probably return to the NBA if he can recover from _____ earlier injury.
__ Why do you suggest buying a new machine? __ Because the old one has been damaged __________.
Is it the days __________you studied in our school ________have a great effect on your maths?