题目

在SO2 + 2 H2S ═ 3 S↓ + 2 H2O中氧化产物和还原产物质量之比为（ ）   A． 2：3          B． 2：1              C． 1：2             D． 3：2 答案：BWith more forests being destroyed, huge quantities of good earth _______ each year.   A. is washing away     B. is being washed away C. are washing away      D. are being washed away