题目

Soon it would be the holidays, but before that, there were year exams. All the 41 had been working hard for some time, reviewing their lessons for the exams. If they didn’t 42 , they would have to retake them in September. There were usually a few who 43  , but Jane didn’t want to be one of them. She had worked hard all year, 44 just before the exams she was working so hard that her sister Barbara was 45 about her. She went to bed too 46  . The night before the first exam, Barbara  47  that she have an early night and take a  48  pill. She promised to wake 49  up in the morn若分式2x+1x-1有意义，则x的取值范围是（　　）A．x≠-12B．x≠1C．x=1D．x=-12