A certain kind of plover, for instance, nests in Canada. At the end of the summer these birds migrate from Canada to South America; they fly 2,500 miles, non-stop, over the ocean.

• 例如，有一种鸻鸟，定巢在加拿大，夏末时，这些鸟从加拿大迁移到南美，它们一刻不停地飞行2，500英里，越过海洋。