39. The city was covered ___by____ smoke from the burns nearby.

40. The police said a notorious criminal was involved___in____the robbery.

41. For most North American household lighting accounts for 10 percent to 15 percent of the electricity bill. However, this amount can be reduced by replacing an ordinary 100. watt light bulb ___with____ an energy saving bulb.

42. The weather is terribly hot, so many boys run to the rivers, jump____in___and swim.

43. Ho Chi Minh devoted all his life to the struggle___of____the liberation of our country.