Another thing that's different about human cells and animal - human cells and bacterial cells is that many bacterial cells can swim and can exist in suspension, that means just suspended in a fluid.

人类细胞和动物细胞--,和细菌细胞,另一个重要不同是,许多细菌细胞可以游动,可以生活在悬浮液中,就是说可以悬浮在液体中

耶鲁公开课 - 生物医学工程探索课程节选