We must do whatever we can to____________the river being polluted any more.
At the back of the book _______ of the works available for further research.
Without the air to hold some of the sun’s heat, the earth at night _____ too cold for us to live.
It sounds like a good idea, but it _________ to be seen whether it will succeed.
---Did you go to the show last night?--- Yeah. Every boy and every girl in the area ____ invited.
you may have , you should gather your courage to face the challenge .