Article: The main crops grown are barley, wheat, buckwheat, rye, potatoes, and assorted fruits and vegetables. Tibet is ranked the lowest among China's 31 provinces on the Human Development Index according to UN Development Programme data. In recent years, due to increased interest in Tibetan Buddhism, tourism has become an increasingly important sector, and is actively promoted by the authorities. Tourism brings in the most income from the sale of handicrafts. These include Tibetan hats, jewelry (silver and gold), wooden items, clothing, quilts, fabrics, Tibetan rugs and carpets. The Central People's Government exempts Tibet from all taxation and provides 90% of Tibet's government expenditures. However most of this investment goes to pay migrant workers who do not settle in Tibet and send much of their income home to other provinces.

Question: From which area does tourism bring the most income?
Ans: sale of handicrafts

Article: To begin with, England had no permanent home stadium. They joined FIFA in 1906 and played their first ever games against countries other than the Home Nations on a tour of Central Europe in 1908. Wembley Stadium was opened in 1923 and became their home ground. The relationship between England and FIFA became strained, and this resulted in their departure from FIFA in 1928, before they rejoined in 1946. As a result, they did not compete in a World Cup until 1950, in which they were beaten in a 10 defeat by the United States, failing to get past the first round in one of the most embarrassing defeats in the team's history.

Question: England played against countries besides the Home Nations for the first time in what year?
Ans: 1908

Article: In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.

Question: What is a QCD?
Ans: vacuum of quantum chromodynamics,

Article: Evidence found in Chinese literature, and archaeological evidence, show that cartography existed in China before the Han. Some of the earliest Han maps discovered were ink-penned silk maps found amongst the Mawangdui Silk Texts in a 2nd-century-BC tomb. The general Ma Yuan created the world's first known raised-relief map from rice in the 1st century AD. This date could be revised if the tomb of Qin Shi Huang is excavated and the account in the Records of the Grand Historian concerning a model map of the empire is proven to be true.

Question: What textile were some of the early Han maps made from?
Ans:
silk