24. A so

25. C to turn

IV

41. If they behaved themselves, their parents would be happy about that

42. If she had said sorry, he wouldn't have been angry

43. If I were a rich businessman, I could afford to buy an expensive car

44. If it hadn't rained last night, I would have gone to the barbecue.

45. If my parents allowed me to go, I wouldn't have stayed at home

V

46. appliances

47. innovations

48. conserve

49. replacing

50. solar

VI

51. I told a joke but nobody laughed

52. You must study harder because you will go into another class

53. I knew her family so I did what I could for her

55. We can't afford energy-saving light bulbs because the light bulbs are too expensive

VII

56. learned

57. don't have

58. attend