Their main job, in collaboration with a protein called fibrin, is to stem the flow of blood from wounds by causing clots.

他们的主要工作是与一种名为纤维蛋白的蛋白质合作，通过产生凝块来阻止伤口的血液流动。

I tied a towel round his leg to try to stem the flow of blood.

【flow】我在他腿上包扎了块毛巾止血。