求用英语翻译五个中文句子

（1）Tibet attribution China,which is located in China's south-west,known as the roof of the world。（2）Tibet's population of about 2。8 million,covers an area of more than 120 million square kilometers。（3）Lhasa,is the world's most expensive city。（4）Tibet has 700 years of history,there are many historical sites,such as the Potala Palace。（5）May 23,1951 since the liberation of Tibet in the political,economic,cultural and other fields have achieved great progress。