一、单选题

1.B ; 2.B; 3.C; 4.B;5.D; 6.D; 7.A; 8.B; 9.D; 10.C; 11.A; 12.D; 13.B; 14.B; 15.C;

16.A; 17.A; 18.A; 19.D; 20.D; 21.B; 22.A; 23.A; 24.B; 25.B; 26.D; 27.B; 28.B; 29.D; 30.C;

31.B; 32.D; 33.A; 34.D; 35.C; 36.D; 37.A; 38.B;39.D; 40.D; 41.D; 42.C; 43.D; 44.C; 45.D; 

46.C; 47.C; 48.D; 49.D; 50.A; 51.C; 52.A;53.D; 54.C; 55.D; 56.A; 57.B; 58.B; 59.C; 60.D; 

61.B; 62.D; 63.C; 64.A; 65.C; 66.D; 67.D; 68.B; 69.D; 70.C; 71.A; 72.A; 73.B; 74.D; 75.B; 

76.B; 77.B; 78.C;