What do the following numbers in the text refer to?
Read the paragraphs given then answer the questions.
1. 2007 (paragraph 2) .
A Swiss company made a new list of wonders in 2007.
2. 220 (paragraph 6) .
They started to build the Great Wall around 220 BC.
3. 1911 ( paragraph 9)
An American explorer discovered the ancient city Machu Picchu in 1911.
4. 39 (paragraph 11)
The Indian emperor’s wife Mümtaz Mahal died at the age of 39.