He arrived____ London ____ a cold winter night.
A. at; at B. in; on C. in; in D. \; on
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
