If you ________ home without a word, your parents wouldn't be so worried now.
--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?
How long do you think the car factory launches a new model?
—Haven’t you solved the problem yet?—Sorry, but I promise it in an hour.
________ the heavy snow came, the weather got colder and colder.
Jackson as well as his classmates going to learn Shakespeare’s works next week, of which some hard to understand.