题目

已知f（x）=|x+1|+|x﹣3|，x1，x2满足x1≠x2，且f（x1）=f（x2）=101，则x1+x2等于（ ） A．0    B．2    C．4    D．6 答案：B【考点】根的存在性及根的个数判断． 【专题】计算题． 【分析】使得函数值是101，需要针对于函数中绝对值内的正负确定去掉绝对值以后的代数式，去掉绝对值以后，解出x的值，把两个自变量的值相加得到结果． 【解答】解：∵f（x）=|x+1|+|x﹣3|， x1，x2满足x1≠x2，且f（x1）=f（x2）=101， 由绝对值阅读下面短文，从短文后各题所给的四个选项（A、B、C和D）中，选出可以填人空白处的最佳选项，并在答题卡上将该项涂黑。Letting go of successI want to make the most of every day. And, like most people, I've _ __ that the best way to do it is to let go of past failures. But that's not all. One can never fully ___ ____ today while thinking too much about past successes, either. People never ___ ___ while resting comfortably on their laurels (荣誉). The __ ____ is that sometimes our successes hold us back more than our failures!I once __ ____ a story about the Oscar owner, actor Clark Gable. A friend ___ ____ Gable one afternoon at the actor's home. She brought along her ___ ____ son, who was playing happily with toy cars on the floor. He ___ ____ he was racing those cars around a great track, which in ___ ____ was an imaginary circle around a golden statue (雕像). The small statue the boy played with was actually the Oscar Clark Gable ___ ____ for his performance in the 1934 movie It Happened One Night.When his mother told him the time had come to __ ____，the little boy asked the actor, “Can I have this？” __ ____ to the Oscar.“Sure，” he smiled. “It's yours.”The horrified mother ___ ____. “Put that back immediately！”Giving the child the golden statue, Clark Gable said, “Having the Oscar around doesn't mean anything to me; ___ __ it does.” The actor seemed to know that past success could be a ___ ____ hammock (吊床) upon which he may be tempted to __ ____， rather than a springboard setting him to begin a new start.You may have learned to let go of past ___ ____ and mistakes in order to free the present. But will you forget past successes and achievements in order to free the ___ ____？ Will your past be a springboard or a restful hammock?“I like the __ ____ of the future better than the history of the past，” said Thomas Jefferson. I ___ ____. After all, the future, not the past, is where the rest of your life will be lived.1.A. discovered B. inferred C. hoped D. worried2.A. spend B. live C. enjoy D. understand3.A. struggle B. work C. learn D. succeed4.A. story B. fact C. idea D. news5.A. heard B. told C. knew D. wrote6.A. saw B. recognized C. met D. visited7.A. careful B. small C. lonely D. clever8.A. pretended B. believed C. insisted D. suggested9.A. case B. reality C. turn D. need10.A. cared B. asked C. looked D. won11.A. act B. leave C. play D. wait12.A. running B. getting C. pointing D. shouting13.A. objected B. noticed C. suffered D. breathed14.A. selling B. keeping C. sharing D. earning15.A. special B. comfortable C. expensive D. necessary16.A. rest B. cheat C. stop D. sit17.A. difficulties B. Events C. failures D. achievements18.A. time B. future C. body D. brain19.A. idea B. meaning C. dreams D. thoughts20.A. obey B. permit C. wish D. agree