题目

如果要干燥氨气，可选用的干燥剂是( ) ①浓硫酸 ②固体氢氧化钠 ③五氧化二磷   ④碱石灰 ⑤固体CaO ⑥无水CaCl2 A．②③④⑤⑥    B．①③⑥     C．②④⑤    D．①②③④⑤ 答案：答案 C  Quit your job after you __________a new one, because it could take a long while. A. found            B. will find        C. had found             D. have found