Problem: Solar energy:

Off-grid PV systems have traditionally used rechargeable batteries to store excess electricity. With grid-tied systems, excess electricity can be sent to the transmission grid, while standard grid electricity can be used to meet shortfalls. Net metering programs give household systems a credit for any electricity they deliver to the grid. This is handled by 'rolling back' the meter whenever the home produces more electricity than it consumes. If the net electricity use is below zero, the utility then rolls over the kilowatt hour credit to the next month. Other approaches involve the use of two meters, to measure electricity consumed vs. electricity produced. This is less common due to the increased installation cost of the second meter. Most standard meters accurately measure in both directions, making a second meter unnecessary.

Why is a second meter usually unnecessary to monitor electricity use?
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A: Most standard meters accurately measure in both directions


Problem: The new Supreme Court of New Zealand was officially established at the beginning of 2004, although it did not come into operation until July. The High Court of New Zealand was until 1980 known as the Supreme Court. The Supreme Court has a purely appellate jurisdiction and hears appeals from the Court of Appeal of New Zealand. In some cases, an appeal may be removed directly to the Supreme Court from the High Court. For certain cases, particularly cases which commenced in the District Court, a lower court (typically the High Court or the Court of Appeal) may be the court of final jurisdiction.
What court's decisions may be appealed to New Zealand's supreme court?
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Answer: Court of Appeal of New Zealand


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Even as the Western Roman empire collapsed, literate men acknowledged that Virgil was a master poet. Gregory of Tours read Virgil, whom he quotes in several places, along with some other Latin poets, though he cautions that "we ought not to relate their lying fables, lest we fall under sentence of eternal death."
What was Gregory of Tours profession?
A: unanswerable


Context and question: The Washington University School of Medicine, founded in 1891, is highly regarded as one of the world's leading centers for medical research and training. The School ranks first in the nation in student selectivity. Among its many recent initiatives, The Genome Center at Washington University (directed by Richard K. Wilson) played a leading role in the Human Genome Project, having contributed 25% of the finished sequence. The School pioneered bedside teaching and led in the transformation of empirical knowledge into scientific medicine. The medical school partners with St. Louis Children's Hospital and Barnes-Jewish Hospital (part of BJC HealthCare), where all physicians are members of the school's faculty.
Who directs the Washington University School of Medicine?
Answer: unanswerable


Question: The effects of the "Twin Shocks"—the Soviet entry and the atomic bombing—were profound. On 10 August the "sacred decision" was made by Japanese Cabinet to accept the Potsdam terms on one condition: the "prerogative of His Majesty as a Sovereign Ruler". At noon on 15 August, after the American government's intentionally ambiguous reply, stating that the "authority" of the emperor "shall be subject to the Supreme Commander of the Allied Powers", the Emperor broadcast to the nation and to the world at large the rescript of surrender, ending the Second World War.
Is there an answer to this question: What was the reply to Japan about the surrender condition?

Answer: "authority" of the emperor "shall be subject to the Supreme Commander of the Allied Powers"


Uranium is more plentiful than antimony, tin, cadmium, mercury, or silver, and it is about as abundant as arsenic or molybdenum. Uranium is found in hundreds of minerals, including uraninite (the most common uranium ore), carnotite, autunite, uranophane, torbernite, and coffinite. Significant concentrations of uranium occur in some substances such as phosphate rock deposits, and minerals such as lignite, and monazite sands in uranium-rich ores (it is recovered commercially from sources with as little as 0.1% uranium).
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What types of rocks sometimes contain uranium?
Ah, so..
phosphate