①此时气体的温度为多少;
②在对缸内气体加热的过程中,气体膨胀对外做功,同时吸收 Q=390J 的热量,则气体增加的内能 △U 多大.
— John, could you please the black-board now? It's your duty today.— OK. I'll do it right away.
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