52. A. edge B. decline C. rise D. air
51. A. communications B. marriages C. exchanges D. associations
50. A. difficult B. likely C. important D. risky
48. A. desert B. leave C. escape D. remove
47. A. greater B. stronger C. narrower D. fewer
46. A. mobility B. motive C. moral D. mission
45. A. However B. Moreover C. Therefore D. Furthermore
44. A. force B. influence C. make D. offer
43. A. order B. ignorance C. guidance D. rudeness
42. A. limited B. identical C. diverse D. distant