人教版英语必修五unit2有一篇reading，是介绍英国的，现在求一篇根据这篇reading自己简述的文章。

The text mainly explains to the learners how the four countries, England, Wales, Scotland and Northern Ireland formed the UK, and how they work together and how they are different.
It also introduces how England can be divided into three different zones geographically and how London was influenced by some of the four invaders culturally and historically and how the evidence of the invasions can be found around the countryside of Great Britain.