你必须保持房间温暖。
他每天可以起来两个小时，但您必须保持房间温暖。
He can get up for about two hours each day, but you must keep the room warm.
因为热空气上升，冬季，吊扇使从天花板到地面之间的气体层循环来保持房间温暖。
Because hot air rises, ceiling fans may be used to keep a room warmer in the winter by circulating the warm stratified air from the ceiling to the floor.
应用推荐