They went fishing ______ a sunny morning.
—What do you think of tomorrow’s football match?—_____difficult for us_____ the match.
You look quite tired. You’d better _____a good rest.
—How long have you _____the novel?—Three days.
—Listen!Helen is singing in the next room.—It _____be Helen .She has gone to Beijing.
Some people won’t realize the importance of their health _____they have lost it.