giúp em với ạ (giải thích ) 21. The police are______ to find out the cause of the crash. A. dividing B. investigating C. indicating D. supplying 22. She _____ injury to win the Olympic gold medal. A. recovered B. suffered C. avoided D. overcame 23. The door____open at any circumstances. A. should not leave B. should left C. shouldn’t be left D. should not be leave 24. We are now facing the possible ____of several rare species A. danger B. variety C. existence D. disappearance 25. _______ to stay the night? -Oh, that’s kind of you A. Why don’t you B. Do you feel like C. Would you like D. Would you mind 26. –A: I’m really tired. __ resting before we go out? –B: That’s a good idea. I’m tired too A. Let’s B. Shall we C. How about D. Why don’t 27. Today, many serious childhood diseases _____ by early immunization A. are preventing B. can prevent C. prevent D. can be prevented 28. The new computer system _______next month A. is being installed by people B. is be installed C. is being installed D. is been installed 29. –I want to explore downtown Hong Kong . - ______ take a minibus? We’ll see a lot more that way A. Let’s not B. What about C. Why don’t we D. Why don’t 30. _____air makes people unpleasant to breathe. A. Pollute B . Pollution C. Polluted D. Polluting 31. Both domestic and imported automobiles must _______ anti-pollution devices A. equip with B. be equipped with C. equip by D. be equipped by 32. The soft background music made her _____ sleepy. A. feel B. to feel C. feeling D. feels 33. This channel allows rain water to run off. A. keep inside B. move around C. flow into D. flow out of