He failed in English once again, but he didn't _______ as if nothing had happened.
Between the two periods of classes is a break,_____we can have a short rest.
With all the novels he was interested in _______, he left the library and went back to his dorm.
--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?
A series of stimulus policies and supportive measures taken by the government _____ to promote change in the economic environment in this area.
---Where did you come across our chemistry teacher ? --- It was in the supermarket ______I purchased mooncakes.