Problem: 51st state:

Puerto Rico has been under U.S. sovereignty for over a century when it was ceded to the U.S. by Spain following the end of the SpanishAmerican War, and Puerto Ricans have been U.S. citizens since 1917. The island's ultimate status has not been determined as of 2012[update], its residents do not have voting representation in their federal government. Puerto Rico has limited representation in the U.S. Congress in the form of a Resident Commissioner, a delegate with limited no voting rights. Like the states, Puerto Rico has self-rule, a republican form of government organized pursuant to a constitution adopted by its people, and a bill of rights.

How long has Congress been U.S. citizens?
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A: unanswerable

Problem: Howard differed from his Labor predecessor Paul Keating in that he supported traditional Australian institutions like the Monarchy in Australia, the commemoration of ANZAC Day and the design of the Australian flag, but like Keating he pursued privatisation of public utilities and the introduction of a broad based consumption tax (although Keating had dropped support for a GST by the time of his 1993 election victory). Howard's premiership coincided with Al Qaeda's 11 September attacks on the United States. The Howard Government invoked the ANZUS treaty in response to the attacks and supported America's campaigns in Afghanistan and Iraq.
In what ways was Howard similar to Paul Keating?
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Answer: pursued privatisation of public utilities and the introduction of a broad based consumption tax

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The Armenians collective has, at times, constituted a Christian "island" in a mostly Muslim region. There is, however, a minority of ethnic Armenian Muslims, known as Hamshenis but many Armenians view them as a separate race, while the history of the Jews in Armenia dates back 2,000 years. The Armenian Kingdom of Cilicia had close ties to European Crusader States. Later on, the deteriorating situation in the region led the bishops of Armenia to elect a Catholicos in Etchmiadzin, the original seat of the Catholicosate. In 1441, a new Catholicos was elected in Etchmiadzin in the person of Kirakos Virapetsi, while Krikor Moussapegiants preserved his title as Catholicos of Cilicia. Therefore, since 1441, there have been two Catholicosates in the Armenian Church with equal rights and privileges, and with their respective jurisdictions. The primacy of honor of the Catholicosate of Etchmiadzin has always been recognized by the Catholicosate of Cilicia.
What are Hamshenis?
A: ethnic Armenian Muslims

Context and question: Even during the war, Eritrea developed its transportation infrastructure by asphalting new roads, improving its ports, and repairing war-damaged roads and bridges as a part of the Warsay Yika'alo Program. The most significant of these projects was the construction of a coastal highway of more than 500 km connecting Massawa with Asseb, as well as the rehabilitation of the Eritrean Railway. The rail line has been restored between the port of Massawa and the capital Asmara, although services are sporadic. Steam locomotives are sometimes used for groups of enthusiasts.
How many km of war-damaged roads has Eritrea fixed?
Answer: unanswerable

Question: There are 29 isotopes of copper. 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper; they both have a spin of 32. The other isotopes are radioactive, with the most stable being 67Cu with a half-life of 61.83 hours. Seven metastable isotopes have been characterized, with 68mCu the longest-lived with a half-life of 3.8 minutes. Isotopes with a mass number above 64 decay by , whereas those with a mass number below 64 decay by +. 64Cu, which has a half-life of 12.7 hours, decays both ways.
Is there an answer to this question: Which isotope makes up about 69% of natural copper?

Answer: 63Cu

QUES: Solar hot water systems use sunlight to heat water. In low geographical latitudes (below 40 degrees) from 60 to 70% of the domestic hot water use with temperatures up to 60 C can be provided by solar heating systems. The most common types of solar water heaters are evacuated tube collectors (44%) and glazed flat plate collectors (34%) generally used for domestic hot water; and unglazed plastic collectors (21%) used mainly to heat swimming pools.

What is a common type of solar water heater?
What is the answer?
ANS:
evacuated tube collectors