This exam is very difficult. Many students are concerned ________the results.
Tony lent me the money, ___ that I’d do as much for him.
不守时是她的典型特征Keeping others waiting ___ her.
AIDS control and prevention is a ___ to China as well as the whole world.
The fresh air on the farm ___ him ___ his headache.
Once ___ light, the film will be damaged and get useless.