@mskathleenquinn @greg_travis It's basically no travel. There is no way to know who is uninfected. Yes places with (enforced) border controls usually had a quarantine scheme to allow "some" travel, but the burden of that reduced travel by something like 99%.
@mskathleenquinn @greg_travis 基本上没有旅行。没有办法知道谁没有被感染。是的，有（强制）边境管制的地方通常有一个检疫计划，允许“一些”旅行，但这种负担减少了大约 99% 的旅行。