题目

如果α、β是一元二次方程x2+3x﹣1=0的两个根，那么α2+2α﹣β的值是    ． 答案：4 ． 解：∵α，β是方程x2+3x﹣1=0的两个实数根， ∴α+β=﹣3，α2+3α﹣1=0即α2+3α=1， 又∵α2+2α﹣β=α2+3α﹣α﹣β=α2+3α﹣（α+β）， 将α+β=﹣3，α2+3α=1代入得， α2+2α﹣β=α2+3α﹣（α+β）=1+3=4．What is it that you love to do but never feel that you get it quite right? Perhaps you don't even try any more because you think what you do is not        enough．Discouragement seems to follow us a good part of the time,        however hard we work, it seems that there is        someone else who can do it much better．I have always enjoyed music and it is        to me that every musician has a        of their own．My father _      several instruments and when he played with other people, it was not difficult to        his sound in a group．Whether it was guitar or another instrument, he had his own        sound．I        heard of a music teacher who commented to a discouraged student, "        else can make the sound that you make．" The sound that you make may not be the same as someone else's, but who is to say which is      ．It is said that, "        is in the eye of the beholder .” . Perhaps it could be said that a delightful sound is in the ear of the       ．Every person has a different tone of voice that        only to them,        we all know people with an unforgettable laugh or a way of        that is unique to them．It might not be the sound of your music or your voice at all．It        be the way you whistle or the sound of your footsteps．Each person has a（an）        on the world in some way．Someone else can do what you do, but they cannot do it        in the same way that you do it．The next time you feel       , remember nobody else can make the sound that you make．小题1:A．easy B．good C．simple D．hard小题2:A．because B．although C．when D．if小题3:A．seldomB．always C．never D．sometimes小题4:A．satisfyingB．convincing C．inspiring D．interesting小题5:A．gift B．sound C．life D．song小题6:A．playedB．designed C．createdD．checked小题7:A．turn down B．call upC．pick out D．give off小题8:A．loud B．powerful C．perfectD．special小题9:A．once B．yetC．even D．still小题10:A．Anybody B．Somebody C．Nobody D．Everybody小题11:A．bigger B．better C．deeper D．lower小题12:A．Beauty B．Interest C．Patience D．Honesty小题13:A．speaker B．receiver C．listener D．looker小题14:A．devotes B．adds C．adapts D．belongs小题15:A．but B．yetC．andD．for小题16:A．running B．walkingC．jumpingD．speaking小题17:A．must B．might C．would D．should小题18:A．choice B．opinionC．duty D．effect小题19:A．exactly B．carefully C．cautiously D．seriously小题20:A．annoyed B．puzzledC．discouragedD．bothered