The children _____ happily in the classroom when the teacher came in.
The children \_\_\_\__ happily in the classroom when the teacher came in.
过去
After driving for twenty miles, he suddenly realized that he has been driving in the wrong direction.
After driving for twenty miles, he suddenly realized that he has been driving in the wrong direction.
It’s time that we _____ to take care of our own house.
It’s time that we \_\_\_\__ to take care of our own house.
During the past ten years, there have been _____ changes in the country.
During the past ten years, there have been \_\_\_\__ changes in the country.
Now I _____ to work by bike instead of by car as there are too many cars on the road in rush hours.
Now I \_\_\_\__ to work by bike instead of by car as there are too many cars on the road in rush hours.
In the past we had only a day off for the whole week: We work every day _____ Sunday.
In the past we had only a day off for the whole week: We work every day \_\_\_\__ Sunday.