The book he's trying to read goes back to long before even the first word was written, and it is a story of migration.

他尝试阅读的这本书可以追溯到很久以前，甚至在第一个字被写出来之前，这是一个关于移民的故事。

youdao

When a banded bird is recaptured and reported, we learn about its migration route, its growth, and how long it has been alive, its lifespan.

当一只被戴了标记环的鸟被重新捕获时，我们就能从报告中了解其迁徙路线、生长情况以及存活时间、寿命。

youdao

lt's a little crazy for me to be writing about migration patterns without actually knowing how they stay underwater for so long.

对我来说，在不知道它们是如何在水下呆这么久的情况下，写它们的洄游模式有点疯狂。

youdao

Few countries see flows of their own citizens, however large or for however long, as migration.

ECONOMIST: Migration statistics

Just over half of those leaving were British, according to the annual report on long-term migration trends.

BBC: Record trends in UK migration

Messenger that have long since made the migration to mobile devices.

FORBES: In 'Killing' The Text Message, Facebook Is Behind The Pack