题型:选择题 The couple _____ some money every month for their future use even though their income can only make ends meet. [ ]A. put off B. put up C. set down D. set aside 查看答案
题型:选择题 海水制备无水氯化镁,主要有以下步骤:①在一定条件下脱水干燥;②加熟石灰; ③加盐酸;④过滤;⑤浓缩结晶。其先后顺序正确的是 [ ]A.②④⑤③① B.③②④①⑤C.③④②⑤① D.②④③⑤① 查看答案