—The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do thejob?—____ my students have a try?
As a writer _____ the new century, he is popular among the teenagers.
_____ the great efforts we had made three years before, we failed to carry our plans through.
Although this medicine can cure you _____ your illness, it has a bad effect _____ you.
He gained his _____ by printing _____ of famous writers.
All of ______ sudden someone shouted, “It is time to put ______ end to the meeting.”