单项选择题
A.Football, volleyball and tennis. B.Volleyball, basketball and ping-pong. C.Basketball, ping-pong and tennis. D.Basketball, football and swimming.
A. Domination. B. Subordination. C. Independence. D. Interdependence.
A. By copying what other people do. B. By making mistakes and having them corrected. C. By listening to explanations from skilled people. D. By asking a great many questions.