64.正在开花　　　　 be in flowers

62.在三层　　　　　 on the third floor

三层楼的建筑　

a building of three storeys/a three-storeyed building

61.扫地　　　　　　 sweep the floor

60.一场大洪水　　　 a big / great flood

59.刹那间　　　　　 in a flash

58.填写表格　　　　 fill in the form

57.关键人物　　　　 a key figure

56.五十多岁时　　　 in one’s fifties

55.科学领域　　　　 the field of science

54.发高烧　　　　　 have a high fever