Mr. Smiths was busy writing a story, only ______ once in a while to smoke a cigarette.
--- I’m not good at singing, you know. ---_________. It’s just for fun.
The schedule, originally ____ out last week, had to be cancelled because of the unexpected snow storm.
Garter Druse ___________ his being selected for the important task to his courage,devotion and knowledge of the area.
---Isn’t it a surprise that I happened to meet Francis Mathews at the Christmas Party last week? ---If my memory serves me correctly, you _____ each other for exactly two years.
When it______air pollution, Beijing faces the three “C” s-----cars,coal and construction,which lead to Beijing's thick air pollution.