We now know that in North America, around 70 percent of bird species migrate.

我们现在知道，在北美，大约 70% 的鸟类会迁徙。

This distance plays a pivotal role in demography, because the patterns in which people migrate to form families determine how genes spread in geographical areas.

这一距离在人口统计学中起着重要的作用，因为人们迁移形成家庭的模式决定了基因如何在地理位置上传播。

He said Monday in Guatemala City that " she didn't have a job and asked me if I would support her" in migrating to the U.S.

他周一在危地马拉城说，她没有工作，并问我是否会支持她移民到美国。

Land prices were inflating to the point where locals were unable to sustain themselves, thus being forced to migrate out to other provinces in order to look for work or trade.

土地价格上涨到当地人无法维持生计的地步，因此被迫迁移到其他省份寻找工作或贸易。