单项选择题A．reproduceB．yieldC．cultivateD．rear
单项选择题A．retainedB．benefitedC．acquiredD．rewarded
单项选择题A．greedyB．indifferentC．sympatheticD．depressed
单项选择题A．contactB．associationC．communicationD．relation
单项选择题A．nobodyB．everybodyC．somebodyD．anybody
