beavers
n. 海狸（beaver 的复数）
v. 勤奋工作（beaver 的第三人称单数）
例句
How about beavers—ecosystems with beavers in waterways.
海狸怎么样——水道中包含海狸的生态系统。
As an example, let's look at foraging behavior among beavers.
作为一个例子，让我们看看海狸的觅食行为。
There used to be beavers all over the place, something like 200 million beavers, just in the continental United States.
在美国大陆，到处都有海狸，大约有2亿只海狸。
