let in on

vt. 告诉(让 ... 知道, 让 ... 参与)

例句与用法：

If they have come along here ten or fifteen years ago they might have been let in on the ground floor of a lot of things.

假如他们在十年或十五年以前来到这我儿的话，他们就可以在许多生意上获得与创办人同等的利益了。

He will never be let in on the arrangements without our consent.

如果没有我们的同意，永远也不会让他知道这种安排。