题目

（2015春•姜堰市期末）如图所示，一名消防队员正沿着竖直悬挂的绳子匀速向下滑行．关于下滑过程，下列几种说法中，不正确的是（ ）    A．  他的运动状态保持不变     B．  他与绳子之间的摩擦是滑动摩擦    C．  他受到的摩擦力方向是向上的        D． 他受到的摩擦力小于重力 答案：D解：A、消防队员向下匀速滑动时，其运动速度和方向都没有发生变化，所以运动状态不变，故A叙述正确； B、消防员胳膊和腿的内侧始终在钢管上不离开钢管，此时消防队员和钢管之间的摩擦是滑动摩擦，故B叙述正确． C、消防队员相对于钢管向下运动，受到摩擦力的方向竖直向上，故C叙述正确． D 阅读理解，阅读下列短文，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。 　　Yesterday I went to our local grocery store．I often go to their deli counter．and I understand that it can get a little confused for the workers．So normally none of them ever take the time to smile or seem overly friendly．But yesterday it was completely different．I was pleasantly surprised to be greeted with a very welcoming smile by the young man behind the counter．He never sighed heavily or slumped back and forth like he didn't want to be there．He was all by himself and quite a long line．But not once did he act concerned about it．He just did his job efficiently anti acted very kind the entire time． 　　I was so impressed that I approached the manager．I explained to her that I often visit the deli counter and I have never been greeted with such kindness．She agreed with me that he was a wonderful person and she thanked me for sharing my feelings with her． 　　As I was walking away, I could hear her approaching the young man with, “I just got a wonderful compliment(praise)about you．”I couldn't hear everything she was saying, but I knew that she did thank him．I couldn't help but smile! 　　Later I had to pass by the deli counter to get onions．There was no one there, except the diligent young man．He didn't say anything, he just smiled at me．I realized that I hadn't done a huge deed that day, but that small deed made a small difference to someone．I love seeing people smile．I just received my smile cards and I wish I had one with me that day．Maybe I will drop one off at the deli a different day! It's amazing how good I felt after that． 　　So, friends, the next time you are in a grocery store, retail store, restaurant, or anywhere that someone is working hard, letting them know in some way can mean so much．I hope you get a smile out ofit like I did! (1) The passage is mainly about ________． [　　] A． friendship between the writer and a young man B． the power of a simple compliment C． a grocery store D． a diligent assistant (2) The writer found it was different yesterday because ________． [　　] A． the young man was very busy B． the young man was concerned about so many customers C． the writer was warmly greeted by a young man D． the young man acted very kind all the time (3) The writer approached the manager to ________． [　　] A． thank him B． say hello to him C． complain about the service D． praise the young man (4) The undedined sentence in Paragraph 4 implies that the writer will ________． [　　] A． smile to others at the deli one day B． give one card to the young man one day C． drop in at the deli one day D． go to the deli for a job one day (5) What can we learn from the last paragraph? [　　] A． Praising others' hard work means nothing． B． Helping others is always rewarding． C． We should never hesitate to praise hard-working persons． D． Not all good deeds deserve praise．