It has been laid down that each student must _____ a composition to the teacher once a week.
It was announced that only when the terrible disease was under control _____ to return to their homes.
Spelling Bee is a contest _____ competitors, usually children, are asked to spell as many words as possible.
When asked to explain _____ he did to make his students so fascinated with his lessons, the teacher paused and thought deeply.
The subway was crowded with passengers going home from market, most of _____ carrying heavy bags and baskets full of fruit and vegetables they had bought there.
—The research on the new flu virus vaccine is challenging and demanding. Who do you think can do the job? —______ my students have a try?