The students didn't return from the end-of-term party until dawn.
BEFORE
Správná odpověď by podle klíče měla být takto:
It was … dawn BEFORE the boys got … back from the end-of-term party.
Já jsem to napsal jinak a chtěl bych vědět, jestli to taky dává smysl:
It was … not BEFORE dawn that the boys got … back form the end-of-term party.