I usually ______ sunglasses outside in the sun.
| A．put on | B．putting on |
| C．wear | D．wearing |
When I walked past her room, I heard her _______ an English song.
| A．singing | B．was singing |
| C．sang | D．is singing |
Keep the machine _______, and you will know how it works.
| A．run | B．to run | C．running | D．runs |
—What was Tom doing _______ it was raining?
—He was doing his homework in the bedroom.
| A．since | B．while | C．when | D．if |
Yesterday, a man said he saw _______ UFO in the park. The police are looking for _______ UFO now.
| A．an; the | B．the; the |
| C．a; the | D．the; an |
He _______ eight hundred thousand dollars for his Benz(奔驰) car.
| A．paid | B．cost | C．took | D．spent |