----Mum, what are you cooking? It smells so _______. ----Oh, cheese cake, of course!I know you enjoy _______ it.
It isn’t a difficult job. I think the children can do it by .
— Li Lei’s grandfather is a Chinese doctor. — So is his father.
After twenty minutes’ walk, the children got to the park.
Jack usually goes skating with his friends the winter vacation.
— David, could you please tell me ? — Every four years.