写一篇英文小短文，要求比较美式英语和英式英语的区别。

The rise of English is a remarkable success story. The earliest history of the English language can be traced back to 450C.D when Jutes invaded Britain, the Anglo-Saxons began to conquer the inhabitants Celts. From the year 450C.D to 1150C.D, it is called Old English Period. Then from 1150 to 1450, it is called Middle English Period, with the great historical event Norman Conquest in the year1066 as its starting point. Then comes the third period, Modern English Period, from the year 1450 to the present. The rapid development of the English language has been promoted by two kinds of tendencies: one aims to enrich and refine English; the other attempts to maintain its purity and simplicity. English is one of the most popular languages in the world. Today, English is used by at least one billion people, and about 400 million speak it as a mother tongue, scattered across every continent and surpassed only by the speakers of Mandarin Chinese. For the other 600 million it ’ s either a se