Ecosystems thus involve the circulation, transformation, and accumulation of energy and matter through the medium of living things and their activities.
因此，生态系统以生物及其活动作为媒介，涉及能量和物质的循环、转化和积累。
2
Red blood cells and specialist immune cells are seen in the sinusoids, pink structures running through the tissue for circulation.
红血细胞和特殊免疫细胞(粉红色部分)在肝窦隙中周而复始地循环。
3
It is in fact this cooling which powers the slow circulation of the mantle, and through that the endless remaking of the surface through plate tectonics.