Paragraph A   When you save electricity, you don’t just save money. You also help to save the planet. Much of our energy comesfrom power plants which burn oil, and this harms the environment. This means that every time you plug in your computer,you’re hurting the planet. Saving electricity is also good for your health. When you turn off the TV, you can get outsideand get some fresh air. To save even more electricity, unplug things when you’re not using them, turn off the lights whenleaving a room, and dry your clothes by hanging them out.
16.When should you unplug things?
(A) At night time.
(B)During the day.
(C)When nobody’s using them.
(D)When they are broken.