例句
So when the atria contract, the valves sandwiched between the atria and the ventricles open, and the blood in each atrium flows through its respective valve down into a ventricle.
所以当你的心房收缩时，夹在心房和心室之间的阀门就打开了，然后每个心房里的血液通过各自的阀门流向心室。
When the heart contracts, the chambers become smaller, forcing blood first out of the atria into the ventricles, then from each ventricle into a large blood vessel connected to the top of the heart.
当心脏收缩的时候，腔室就变小了，压迫着血液从心房进入心室，然后从每一个心室进入与心脏上部相连的大血管。