The two men quarrelled bitterly and it was clear that the ar

1、that是主语从句.
断句如下：
The two men quarrelled bitterly
and (递进）
it was clear
that （that后面内容代替it部分的内容）
the argument could only be settled by a fight.
2、状语从句.
It was not until his third match in 1790
that
he finally beat Humphries and became Champion of England.