You can’t imagine the difficulty he ________onto the cliff and saving the boy in trouble.
_____ people are waiting to watch the raising of the national flag at Tian’an Men Square.
The new library building _____ last week.
—Did you call Sara back?—I didn’t need to, _____ we’ll have a meeting together tonight.
Keep practicing and you _____ your English.
The air in mountain areas is ____ that in big cities.