32. If we go ................wasting water, there will be a shortage of fresh water in a few decades. A. off B. on C. of D. to 33. I really enjoy Math class ................the teacher is very good. A. so B. because C. therefore D. but 34. Who will take care of your children when you are away? (CLOSEST) A. look for B. look out C. look up D. look after 35. For most household, lighting accounts ...............10 percent to 15 percent of the electricity bill. A. in B. for C. to D. of 36. Energy-saving bulbs should be used to .......................electricity. A. save B. produce C. waste D. keep 37. I’d love to go to the party ...................I have to finish my homework. A. or B. and C. but D. so 38. You have to .......................your toys and go to bed. It’s late. A. put away B. throw away C. go off D. take off