单项选择题
A. oil and coal B. solar energy C. the heat of the sun D. water supply
A. she quarreled with her husband and she was very angry B. she wanted to buy a new car for her husband C. the car was too old D. the car was out of order
A. give children correct answers B. point out children’s mistakes to them all the time C. allow children to mark their own work D. encourage children to copy from one another