“三天后”的英语翻译，用in什么什么

in three days

根据语境翻译“三天后”

过去时：after three days或者是three days later
将来时：in three days

特殊句式的使用

三天之后才做了某事：didn't do something until three days later
强调句（强调时间状语）：It is after three days that ... 或者是
It is not until three days later that...

In three days 或 In three days' time 是“三天之内”。“三天后”是 After three days 或 After three days' time。
 

别误导人哦，in three days也可以表示在3天后，这就是正解

yes,
in three days.

in three days' time