Input: Read this: The permanent dissolution of clouds allows unhindered light and thermal radiation. The stability of the atmosphere above the desert prevents any convective overturning, thus making rainfall virtually non-existent. As a consequence, the weather tends to be sunny, dry and stable with a minimal risk of rainfall. Subsiding, diverging, dry air masses associated with subtropical high-pressure systems are extremely unfavorable for the development of convectional showers. The subtropical ridge is the predominate factor that explains the hot desert climate (Koppen climate classification BWh) of this vast region. The lowering of air is the strongest and the most effective over the eastern part of the Great Desert, in the Libyan Desert which is the sunniest, the driest and the most nearly rainless place on the planet rivaling the Atacama Desert, lying in Chile and Peru.
Question: What is caused by the atmospheres in-stability?

Output: unanswerable

Input: Read this: The main passenger airport serving the metropolis and the state is Melbourne Airport (also called Tullamarine Airport), which is the second busiest in Australia, and the Port of Melbourne is Australia's busiest seaport for containerised and general cargo. Melbourne has an extensive transport network. The main metropolitan train terminus is Flinders Street Station, and the main regional train and coach terminus is Southern Cross Station. Melbourne is also home to Australia's most extensive freeway network and has the world's largest urban tram network.
Question: What country has the world's largest urban tram network?

Output: Australia

Input: Read this: The Houston area has over 150 active faults (estimated to be 300 active faults) with an aggregate length of up to 310 miles (500 km), including the Long PointEureka Heights fault system which runs through the center of the city. There have been no significant historically recorded earthquakes in Houston, but researchers do not discount the possibility of such quakes having occurred in the deeper past, nor occurring in the future. Land in some areas southeast of Houston is sinking because water has been pumped out of the ground for many years. It may be associated with slip along the faults; however, the slippage is slow and not considered an earthquake, where stationary faults must slip suddenly enough to create seismic waves. These faults also tend to move at a smooth rate in what is termed "fault creep", which further reduces the risk of an earthquake.
Question: What is the total length of the Houston faults?

Output: 310 miles

Input: Read this: As a member of the European Union, Estonia is considered a high-income economy by the World Bank. The GDP (PPP) per capita of the country, a good indicator of wealth, was in 2015 $28,781 according to the IMF, between that of Slovak Republic and Lithuania, but below that of other long-time EU members such as Italy or Spain. The country is ranked 8th in the 2015 Index of Economic Freedom, and the 4th freest economy in Europe. Because of its rapid growth, Estonia has often been described as a Baltic Tiger beside Lithuania and Latvia. Beginning 1 January 2011, Estonia adopted the euro and became the 17th eurozone member state.
Question: What institution views the economy of Estonia as high income?

Output:
the World Bank