--- The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do the job?---____ my students have a try?
So many brand marks _____each other that we had great difficulty finding the one he referred to.
You may have no idea _____ you will be doing ten years from now.
_______________, we don’t have much spare time at the moment.
It is the education _____ he received when studying abroad _____ has made him such an excellent manager.
--Mum, I’m going to visit my uncle. What about staying there a week? --A week is too long. Try to be back in a _____ of days.