题目

如图，在水平桌面上放置一斜面体 P，两长方体物块 a 和 b 叠放在 P 的斜面上，a、b、c 质量分 别为 2m、m、m，斜面倾角为，整个系统处于静止状态．若将 a 和 b、b 与 P、P 与桌面之间摩擦力的大小分别用 f1、f2 和 f3 表示．则 A． B． C． D． 答案：A 【解析】 对物体分析物体受重力，绳子的拉力，根据平衡条件可得；对物体分析可知物体受重力，支持力，绳子的拉力的作用，根据平衡条件可得受到的摩擦力；再对整体分析可知整体受重力，支持力，绳子的拉力的作用，根据平衡条件可得受到的摩擦力，方向沿斜面向上；对及组成的整体分析可知26、 “Can you work outdoors in any weather?” “How would you like a job working with children?” Before this year, US public school students rarely（极少的）had to answer such questions about their possible future careers （职业）.    But now, public schools in 24 states are developing new learning plans for each student, according to the US Education Commission （教育部）. The learning plans will help students discover their own strengths and weaknesses. （A） They will also give parents and teachers a more complete（完整的）report besides grades.    Linwood Middle School, in North Brunswick, New Jersey, is one of these schools. Students there take an online test （B） called Matchmaker to make learning plans for their future careers. This online test uses some information about students’ （C） learning styles, personal interests, skills and career goals.    （D） “If you don’t know yourself and want to be scientist, you may realize in college you don’t like science,” said Mercedes Arias, a Linwood language arts teacher. “The learning plans can （E）________ ________ better prepare students for college _______ _______ encourage students to work harder.”    Daniella Martins, 14, a Linwood ninth grader, dreams of （F） _________ （be） a singer or an actress. （G）“Nobody likes to take tests,” she said before the career test. But she was pleased with the results, which listed her top career as the arts, followed by education and human services.    “The results show that I have a great possibility to be a singer,” said Martins. “But I know I’ll still have to work hard to （H） make it.” 任务一：根据短文内容，回答下面两个问题。 1. What do students in Linwood Middle School take an online test for? __________ 2. According to Daniella’s test result, what is she most likely to become? _________ 任务二：将（A）、（D）、（G）处划线句子翻译成汉语。 （A）3. ____________________________________________________ （D）4. ____________________________________________________ （G）5. ____________________________________________________ 任务三：写出（C）处划线短语的汉语意思：   （C）6. ______________________ 任务四：写出（B）处和（H）处划线单词和短语的同义词： 7. （B）__________   （H）___________ 任务五：在 （E） 处句子中的空白处填入合适的单词： 8. ________________________________ 任务六：在（F）处用所给单词的适当形式填空： 9. ___________________ 任务七：在文中找出能概括主题的句子。 10. _____________________________________________