Problem: Copper:

Copper occurs naturally as native copper and was known to some of the oldest civilizations on record. It has a history of use that is at least 10,000 years old, and estimates of its discovery place it at 9000 BC in the Middle East; a copper pendant was found in northern Iraq that dates to 8700 BC. There is evidence that gold and meteoric iron (but not iron smelting) were the only metals used by humans before copper. The history of copper metallurgy is thought to have followed the following sequence: 1) cold working of native copper, 2) annealing, 3) smelting, and 4) the lost wax method. In southeastern Anatolia, all four of these metallurgical techniques appears more or less simultaneously at the beginning of the Neolithic c. 7500 BC. However, just as agriculture was independently invented in several parts of the world, copper smelting was invented locally in several different places. It was probably discovered independently in China before 2800 BC, in Central America perhaps around 600 AD, and in West Africa about the 9th or 10th century AD. Investment casting was invented in 45004000 BC in Southeast Asia and carbon dating has established mining at Alderley Edge in Cheshire, UK at 2280 to 1890 BC. Otzi the Iceman, a male dated from 33003200 BC, was found with an axe with a copper head 99.7% pure; high levels of arsenic in his hair suggest his involvement in copper smelting. Experience with copper has assisted the development of other metals; in particular, copper smelting led to the discovery of iron smelting. Production in the Old Copper Complex in Michigan and Wisconsin is dated between 6000 and 3000 BC. Natural bronze, a type of copper made from ores rich in silicon, arsenic, and (rarely) tin, came into general use in the Balkans around 5500 BC.[citation needed]

When did Natural bronze start to be used by the general public?
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A: 5500 BC

Problem: Anxious to expand the company's broadcast and cable presence, longtime MCA head Lew Wasserman sought a rich partner. He located Japanese electronics manufacturer Matsushita Electric (now known as Panasonic), which agreed to acquire MCA for $6.6 billion in 1990. Meanwhile, around this time, the production subsidiary was renamed Universal Studios Inc., and (in 1990) MCA created MCA/Universal Home Video Inc. for the VHS video cassette (later DVD) sales industry.
What company created the VHS cassette?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The Pamiri people of Gorno-Badakhshan Autonomous Province in the southeast, bordering Afghanistan and China, though considered part of the Tajik ethnicity, nevertheless are distinct linguistically and culturally from most Tajiks. In contrast to the mostly Sunni Muslim residents of the rest of Tajikistan, the Pamiris overwhelmingly follow the Ismaili sect of Islam, and speak a number of Eastern Iranian languages, including Shughni, Rushani, Khufi and Wakhi. Isolated in the highest parts of the Pamir Mountains, they have preserved many ancient cultural traditions and folk arts that have been largely lost elsewhere in the country.
What people are not distinct linguistically and culturally from most Tajiks?
A: unanswerable

Context and question: The arts of Southeast Asia have affinity with the arts of other areas. Dance in much of Southeast Asia includes movement of the hands as well as the feet, to express the dance's emotion and meaning of the story that the ballerina is going to tell the audience. Most of Southeast Asia introduced dance into their court; in particular, Cambodian royal ballet represented them in the early 7th century before the Khmer Empire, which was highly influenced by Indian Hinduism. Apsara Dance, famous for strong hand and feet movement, is a great example of Hindu symbolic dance.
Where did the Southeast Asians introduce their dance?
Answer: into their court

Question: The firm continued to pressure Kelsey and the agency to approve the applicationuntil November 1961, when the drug was pulled off the German market because of its association with grave congenital abnormalities. Several thousand newborns in Europe and elsewhere suffered the teratogenic effects of thalidomide. Though the drug was never approved in the USA, the firm distributed Kevadon to over 1,000 physicians there under the guise of investigational use. Over 20,000 Americans received thalidomide in this "study," including 624 pregnant patients, and about 17 known newborns suffered the effects of the drug.[citation needed]
Is there an answer to this question: When was the drug taken off shelves in the USA?

Answer: unanswerable

Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different regions may use different supply voltages and frequencies, complicating through service. The limited clearances available under catenaries may preclude efficient double-stack container service. The lethal voltages on contact wires and third rails are a safety hazard to track workers, passengers and trespassers. Overhead wires are safer than third rails, but they are often considered unsightly.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Why overhead wires are not being widely used?
Ah, so..
considered unsightly.