魚はエラを通して水中の酸素を循環させる。
Sakana wa era o tooshite suichuu no sanso o junkan saseru.
Fish circulate oxygen from the water through their gills.
体内の血液循環は生命維持に不可欠だ。
Tainai no ketsuekijunkan wa seimei iji ni fukaketsu da.
Blood circulation within the body is essential for maintaining life.