题目

10名运动员中有2名老队员和8名新队员，现从中选3人参加团体比赛，要求老队员至多1人入选且新队员甲不能入选的选法有（ ）种． A．77   B．144  C．35   D．72 答案：a考点】排列、组合的实际应用． 【专题】计算题；分类讨论；综合法；排列组合． 【分析】分两类，第一类，3人中有1名老队员2名新队员，第二类，3人全部是新队员，分别计算两类的选法种数，相加可得答案． 【解答】解：分两类，第一类，有1名老队员2名新队员，共有=42种选法； 第二类，3人全部根据句意及首字母完成单词。1. Alice trusts you, only you can p _____ her to give up the foolish idea.2. Some schools teach, but fail to e _____ their students.3. Doing more e _____ is good for you.4. He wants to write something about s _____ healthy.5. Eating junk food has many d _____ for the children.6. Can you say some kinds of t _____ school meal?7. He has r _____ his mistakes. He felt very sorry about that.8. When you sit at a restaurant, the waiter often shows you m _____ at first.9. Don't eat too much s _____ , it's bad for teeth.10. He has a great i _____ in sports and he often watches sports programmes on TV.