Question: In the far north, there is a division between Berber-descendent Tuareg nomad populations and the darker-skinned Bella or Tamasheq people, due the historical spread of slavery in the region. An estimated 800,000 people in Mali are descended from slaves. Slavery in Mali has persisted for centuries. The Arabic population kept slaves well into the 20th century, until slavery was suppressed by French authorities around the mid-20th century. There still persist certain hereditary servitude relationships, and according to some estimates, even today approximately 200,000 Malians are still enslaved.
Is there an answer to this question: Roughly how many Malians are descendants of slaves?

Answer: 800,000

Question: The Industrial Revolution in the Midlands and Northern England spelled the end for most of Somerset's cottage industries. Farming continued to flourish, however, and the Bath and West of England Society for the Encouragement of Agriculture, Arts, Manufactures and Commerce was founded in 1777 to improve farming methods. Despite this, 20 years later John Billingsley conducted a survey of the county's agriculture in 1795 and found that agricultural methods could still be improved. Coal mining was an important industry in north Somerset during the 18th and 19th centuries, and by 1800 it was prominent in Radstock. The Somerset Coalfield reached its peak production by the 1920s, but all the pits have now been closed, the last in 1973. Most of the surface buildings have been removed, and apart from a winding wheel outside Radstock Museum, little evidence of their former existence remains. Further west, the Brendon Hills were mined for iron ore in the late 19th century; this was taken by the West Somerset Mineral Railway to Watchet Harbour for shipment to the furnaces at Ebbw Vale.
Is there an answer to this question: What flourished in Somerset after the Industrial revelotuion

Answer: Farming continued to flourish

Question: New York City is supplied with drinking water by the protected Catskill Mountains watershed. As a result of the watershed's integrity and undisturbed natural water filtration system, New York is one of only four major cities in the United States the majority of whose drinking water is pure enough not to require purification by water treatment plants. The Croton Watershed north of the city is undergoing construction of a US$3.2 billion water purification plant to augment New York City's water supply by an estimated 290 million gallons daily, representing a greater than 20% addition to the city's current availability of water. The ongoing expansion of New York City Water Tunnel No. 3, an integral part of the New York City water supply system, is the largest capital construction project in the city's history.
Is there an answer to this question: After the water purification plant at the Croton Watershed is built, how much more water will be added to the city's supply each day?

Answer: 290 million gallons

Question: Vacuum is useful in a variety of processes and devices. Its first widespread use was in the incandescent light bulb to protect the filament from chemical degradation. The chemical inertness produced by a vacuum is also useful for electron beam welding, cold welding, vacuum packing and vacuum frying. Ultra-high vacuum is used in the study of atomically clean substrates, as only a very good vacuum preserves atomic-scale clean surfaces for a reasonably long time (on the order of minutes to days). High to ultra-high vacuum removes the obstruction of air, allowing particle beams to deposit or remove materials without contamination. This is the principle behind chemical vapor deposition, physical vapor deposition, and dry etching which are essential to the fabrication of semiconductors and optical coatings, and to surface science. The reduction of convection provides the thermal insulation of thermos bottles. Deep vacuum lowers the boiling point of liquids and promotes low temperature outgassing which is used in freeze drying, adhesive preparation, distillation, metallurgy, and process purging. The electrical properties of vacuum make electron microscopes and vacuum tubes possible, including cathode ray tubes. The elimination of air friction is useful for flywheel energy storage and ultracentrifuges.
Is there an answer to this question: What are lightbulbs used to study?

Answer:
unanswerable