I. Type of writing and summary of the ideas

Type of writing

This is a piece of expository writing. 说明文

Main idea of the passage

It tells us about the puzzles in the historical geography of London.

Central idea of 1^st paragraph

Why are different words used to describe England, Wales, Scotland and Northern Ireland?

Central idea of 2nd paragraph

First there was England.

Central idea of 3rd paragraph

Great Britain was the name given when England and Wales were joined to Scotland.

Central idea of 4th paragraph

The four countries are still very different.

Central idea of 5th paragraph

England is the largest of the four countries.

Central idea of 6th paragraph

The greatest historical treasure of all is London.