题目

密封在体积一定的容器内的气体，当温度升高时，正确的是（    ）A.气体分子密度增大                        B.气体分子平均动能增加C.气体的内能增加                          D.气体的压强增大 答案：解析：由于体积不变，故分子密度不变，A项错.温度升高平均动能增大，内能增加，平均速率增大，压强增大.答案：BCD ______the earth with the sun on the map, the boy concluded that the earth is much smaller.   A. Comparing 　 B. Compared   C. Having compared   D. Having been compared