题目

---Does Rita feel better today? ---Her condition has        improved, but it will be some time before she returns to school． A．sooner or later                                            B．more or less C．now and then                                             D．once in a while 答案：B-π/2<2α<β<π/2，则2α-β的范围是A.-π<2α-β<0B.-π<2α-β<πC.-3π/2<2α-β<π/2D.0<2α-β<π