题目

 —What’s your mother’s job?—    A. She is reading.                    B. She is 40 years old.C. She wants to be a teacher.   D. She is a manager. 答案：D下列说法正确的是（ ）A. 气体对外界做功，其内能一定减小B. 气体从外界吸热，其内能一定增大C. 温度越高，分子热运动越剧烈D. 温度越低，分子的平均动能越大