题目

下列物质敞口放置于空气中，质量会增加的是 A．食盐水          B．石灰石          C．浓盐酸          D．浓硫酸 答案：D I prefer ________ at home to ________ outside． [　　] A． staying, play B． to stay, play C． staying, playing D． to stay, playing