24. A. went by B. set off C. got there D. came on
23. A. fast B. ahead C. soon D. later
22. A. anxious B. sweet C. gentle D. low
21. A. ambulance B. truck C. car D. bus
19. As you can see, the number of cars on roads _______ rising these days.
A. keeping B. keep C. keeps D. were keeping
18. The farmers use dogs to their cows at night.
A. take care B. 1ook up C. watch over D. turn to
17. Although he explained again and again, he could not make himself ______ by all of us.
A. understand B. understanding C. understood D. be understood
16. It was the old clock that the old man spent the whole morning at home.
A. repairing B. repaired C. to repair D. in repair
15. In recent years _____ global warming is becoming _____ concern for people all over the world.
A. the; the B. ∕; a C. ∕; ∕ D. The; ∕