1. For a while it looked as though the North might win.

as though：似乎，貌似

e.g. He likes to talk big as though he was an important person.

他老爱说大话，就仿佛他是一位要人似的。

e.g. He kept silent,eating just as conscientiously but as though everything tasted alike.

他一声不吭，闷头吃着，仿佛桌上的饭菜都一个味儿。

2. As rebels swept through Lancashire, Yorkshire and Northumberland, it must have seemed that Catholic Britain had been reborn.

sweep through： (使)扫过…...； (使)掠过…...； (使)迅速传遍于…...

e.g. Can you hear the wind sweeping through the branches?

你能听到风掠过树枝的声音吗?

e.g. The news swept through the village like fire.

那消息像火一样在村中蔓延。

e.g. The disease can sweep through whole populations in a very short time.

这种病可以在很短的时间里在全体人口中流行开来。

3. Now Elizabeth's government really knew what it was up against, the latest act in the endlessly drawn out religious war that began when Henry VIII made himself Supreme Head of the Church.

up against：面对

e.g. Although he ran up against many difficulties, he did not lose heart.

虽然他碰到了许多困难，但他并不气馁。

e.g. Don't back up the moment you run up against a little difficulty.

不要遇到一点困难就打退堂鼓。