You decide that your users would not like to see welcome messages disappear after they've been added, so you choose not to delete any records within the down migration.

它认定用户在加入之后不想看到欢迎信息消失，所以选择向下迁移时不删除任何记录。

youdao

There is growing support for the theory that migration took place much earlier, by sea, following a coastal route along Alaska and down the northwest coast.

越来越多的人支持这样一种理论，即移民发生得要早得多，是沿着阿拉斯加沿海路线，沿西北海岸而下通过海路进行的。

youdao

Nevertheless, you can realize huge benefits from this task â “ not only for the organizational planning, but also for the rest of the migration, down to operation and maintenance.

无论如何，可以通过这个任务获得巨大的收益 —— 不仅对于组织规划有好处，对于迁移过程的其余部分直至操作和维护，都很有好处。

youdao

But he says even as France cracks down on family migration and sends illegal immigrants back home, it is making it easier for highly-skilled immigrants to come in.

VOA: standard.2010.01.20

The researchers said the global economic crisis would only slow down migration rates temporarily.

BBC: Britain 'biggest in EU by 2050'

Rapid industrial growth over the past three decades has required tearing down migration barriers to exploit the countryside's huge labour surplus.

ECONOMIST: Migration in China

This allows travellers a chance to get a sneak peek of the migration down south before indulging in the crowd-free wildlife show of the north.

BBC: The Serengeti in the off-season