Tigers wait ______ it is dark, then they go out to find their food.
—Do you walk to school every day? —I used to walk, but now I ride to school _______ walking.
______ careful you are, ______mistakes you will make.
—Do you know if he ____ to play football with us? —I think he will come if he _____ free tomorrow.
This place is worth _______.
Not only his parents but also he ____ watching football games on TV.