题目

若代数式有意义，则实数x的取值范围是（ ） A．x≥1                 B．x≥2                  C．x＞1                 D．x＞2 答案：B解：根据题意得， 解得x≥2．The servant broke the vase that I ________ for twenty years.A.had haveB.had keptC.had takenD.had bought