Problem: Geological history of Earth:

South America became linked to North America through the Isthmus of Panama during the Pliocene, bringing a nearly complete end to South America's distinctive marsupial faunas. The formation of the Isthmus had major consequences on global temperatures, since warm equatorial ocean currents were cut off and an Atlantic cooling cycle began, with cold Arctic and Antarctic waters dropping temperatures in the now-isolated Atlantic Ocean. Africa's collision with Europe formed the Mediterranean Sea, cutting off the remnants of the Tethys Ocean. Sea level changes exposed the land-bridge between Alaska and Asia. Near the end of the Pliocene, about 2.58 million years ago (the start of the Quaternary Period), the current ice age began. The polar regions have since undergone repeated cycles of glaciation and thaw, repeating every 40,000100,000 years.

How often does the cycle of rising sea levels repeat?
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A: unanswerable

Problem: An analysis of the evolution of mass media in the US and Europe since World War II noted mixed results from the growth of the Internet: "The digital revolution has been good for freedom of expression [and] information [but] has had mixed effects on freedom of the press": It has disrupted traditional sources of funding, and new forms of Internet journalism have replaced only a tiny fraction of what's been lost.
What was disrupted by Internet growth for the press?
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Answer: traditional sources of funding

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
On March 17, 1991, an all-Russian referendum created the post of President of the RSFSR. On June 12, Boris Yeltsin was elected President of Russia by popular vote. During an unsuccessful coup attempt on August 1921, 1991 in Moscow, the capital of the Soviet Union and Russia, President of Russia Yeltsin strongly supported the President of the Soviet Union, Mikhail Gorbachev.
Who was the President of the Soviet Union in 1991?
A: Mikhail Gorbachev

Context and question: The name "Seattle" appears on official Washington Territory papers dated May 23, 1853, when the first plats for the village were filed. In 1855, nominal land settlements were established. On January 14, 1865, the Legislature of Territorial Washington incorporated the Town of Seattle with a board of trustees managing the city. The town of Seattle was disincorporated January 18, 1867 and remained a mere precinct of King County until late 1869, when a new petition was filed and the city was re-incorporated December 2, 1869 with a Mayor-council government. The corporate seal of the City of Seattle carries the date "1869" and a likeness of Chief Sealth in left profile.
At what date did the name Seattle first appear on official papers?
Answer: May 23, 1853

Question: The United States shares land borders with Canada (to the north) and Mexico (to the south), and a territorial water border with Russia in the northwest, and two territorial water borders in the southeast between Florida and Cuba, and Florida and the Bahamas. The contiguous forty-eight states are otherwise bounded by the Pacific Ocean on the west, the Atlantic Ocean on the east, and the Gulf of Mexico to the southeast. Alaska borders the Pacific Ocean to the south, the Bering Strait to the west, and the Arctic Ocean to the north, while Hawaii lies far to the southwest of the mainland in the Pacific Ocean.
Is there an answer to this question: Hawaii lays far to the north east in what ocean?

Answer: unanswerable

QUES: Old Persian is the Old Iranian dialect as it was spoken in south-western Iran by the inhabitants of Parsa, who also gave their name to their region and language. Genuine Old Persian is best attested in one of the three languages of the Behistun inscription, composed circa 520 BC, and which is the last inscription (and only inscription of significant length) in which Old Persian is still grammatically correct. Later inscriptions are comparatively brief, and typically simply copies of words and phrases from earlier ones, often with grammatical errors, which suggests that by the 4th century BC the transition from Old Persian to Middle Persian was already far advanced, but efforts were still being made to retain an "old" quality for official proclamations.

During what century was the change from old to middle Persian just beginning?
What is the answer?
ANS:
unanswerable