题目

菱形在平面直角坐标系中的位置如图13所示，，则点的坐标为_____________.  答案：（+1，1）解析:作CD⊥x轴于点D，∵四边形OABC是菱形，OC=，∴OA=OC=，又∵∠AOC=45°∴△OCD为等腰直角三角形，∵OC=，∴OD=CD=OCsin45°=1，则点C的坐标为（1，1），又∵BC=OA=，∴B的横坐标为OD+BC=1+，B的纵坐标为CD=1，则点B的坐标为（+1，1）． It is quite reasonable to blame traffic jams, the cost of gas and the great speed of modern life, but manners on the road are becoming horrible. Everybody knows that the nicest men would become fierce tigers behind the wheel. It is all right to have a tiger in a cage, but to have one in the driver’s seat is another matter altogether. Road politeness is not only good manners, but good sense too. It takes the most cool-headed drivers great patience to give up the desire to beat back when forced to face rude driving. On the other hand, a little politeness goes a long way towards reducing the possibility of quarrelling and fighting. A friendly nod or a wave of thanks in answer to an act of politeness helps to create an atmosphere of good will and calm so necessary in modern traffic conditions. But such behaviors of politeness are by no means enough. Many drivers nowadays don’t even seem able to recognize politeness when they see it. However, misplaced politeness can also be dangerous. Typical examples are the driver who waves a child crossing the street at a wrong place into the path of oncoming cars that may be not able to stop in time. The same goes for encouraging old ladies to cross the road wherever and whenever they want to. It always amazes me that the highways are not covered with the dead bodies of these grannies. An experienced driver, whose manners are faultless, told me it would help if drivers learnt to correctly join in traffic stream without causing total blockages that give rise to unpleasant feelings. Unfortunately, modern drivers can’t even learn to drive, let alone master the roadmanship. Years ago, experts warned us that the fast increase of the car ownership would demand more give-and-take from all road users. It is high time for all of us to take this message to heart. 小题1:According to the passage, troubles on the road are often caused by _______.A．road conditionsB．the speed of modern life C．the behavior of the driversD．the large number of cars小题2:In the writer’s opinion, ________.A．drivers should avoid traffic jamsB．strict traffic rules are badly needed C．unskillful drivers should be punishedD．drivers should show road politeness properly小题3:The underlined word “give-and-take” in the last paragraph means “______”.A．politeness and impoliteness B．good manners and bad manners C．offering help to others as much as possible D．willingness of each person to give in to each other’s wishes小题4:What is the best title of the passage?A．Road politeness B．Traffic problems C．Bad manners on the roadD．Good divers and bad drivers