等等，我明白你的意思了，但在我们讨论欧洲人的定居如何影响生态系统之前，告诉我，海狸生活在怎样的环境中？
Wait, I see where you are heading with this, but before we go into how European settlement affected the ecosystem, tell me this—what kind of environment do beavers live in?
农业是在大自然中进行的；大自然里的生态系统中各种生物和活动相互影响，而粮食的生产正是处在这样的生态环境中。
Agriculture takes place in nature, among ecosystems of interacting organisms and activity, and crop production takes place within that ecosystem environment.
环境因素的影响以及在元社区水平上研究群落系统发育有助于理解区域生态进程。
The influence of environmental factors and studying community phylogeny at the metacommunity level helps to understand regional ecological processes.
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