当中【dāngzhōng】

当中 follows a noun for a group and picks someone or something out of it, "among, of". 在 in front is optional.

It pairs naturally with 最 and with 有.

In the course of

After a period or an activity, 在…当中 means "during, in the course of".

In a room or a space, 当中 is simply "in the middle".

After the noun, not before

当中 comes after the group, the reverse of English "among us".

• × 当中我们谁最高 → 我们当中谁最高

其中 also means "among them", but it stands alone at the start of a clause, pointing back to a group already named; 当中 needs the group right in front of it.