题目

三个数 ，， 3在数轴上从左到右依次排列，求a的取值范围． 答案：解：由题意得{1−2a<a−1a−1<3，解得{a>23a<4∴a的取值范围是23<x<4．“What time does the plane _________?” “I think at about 10 o’clock.”  A．drop off          B．get off            C．take off           D．turn off