Seeing the road ________ with snow, they had to stay at home, watching TV and drinking coffee.
Since Tom ______ downloaded a virus into his computer, he can not open the file now.
He began to take political science ____ only when he left school.
She devoted herself ______ to her research and it earned her a good reputation in her field.
The committee is discussing the problem right now. It will_____ have been solved by the end of next week.
一Have you handed in your schoolwork yet? 一Yes,I have.I guess it _____ now.