the upper短语¹⁵¹¹ 基本例句 un.上唇；🌏河流的上游；上铺；上部 This forces blood out of the exit valves and into the body, and by the time the lower chambers and exit valves relax, the upper chambers and entry valves are receiving another electric prompt. 这个迫使血液流出出口阀门，流向身体各部。 当底下的心腔和出口阀门处于放松状态时，上面的心腔和入口阀门会接受到另一个电子刺激。 yeeyan