阅读下面的短文，在标有序号的空白处填入一个适当的词，或填入括号中单词的正确形式，并将相应答案写在答题卷上。
If you study British history, you can easily      the problem about the names of the four countries. Wales was      to England in the 13^th century, which was followed by Scotland in 1603. And it was only after Northern Ireland joined with them that the UK finally came into     , which was shown in its new flag --- the      Jack.
England, the largest of the four, is       into three zones for convenience, that is, the South, the Midlands, and the North. The great historical         of all is London. It owns famous museums, art      , theatres, parks and famous building, all of which have been influenced greatly by four sets of      in history.