51. A. quick B. huge C. heavy D. stupid
50. A. until B. when C. before D. though
49. A. push B. lock C. guard D. defend
48. A. hit B. saved C. frightened D. killed
47. A. crying B. smoking C. singing D. laughing
46. A. an exciting B. a calm C. an angry D. a natural
45. A. South Africa B. America C. South Asia D. Europe
44. A. on B. above C. over D. from
43. A. open B. close C. pull D. draw
42. A. some difficulty B. a thief C. some danger D. an accident