Question: Commercial solar water heaters began appearing in the United States in the 1890s. These systems saw increasing use until the 1920s but were gradually replaced by cheaper and more reliable heating fuels. As with photovoltaics, solar water heating attracted renewed attention as a result of the oil crises in the 1970s but interest subsided in the 1980s due to falling petroleum prices. Development in the solar water heating sector progressed steadily throughout the 1990s and growth rates have averaged 20% per year since 1999. Although generally underestimated, solar water heating and cooling is by far the most widely deployed solar technology with an estimated capacity of 154 GW as of 2007.
Is there an answer to this question: When did the use of solar water heaters in the US first begin?

Answer: in the 1890s


Question: As a division within the BBC, Television was formerly known as BBC Vision for a few years in the early 21st century, until its name reverted to Television in 2013. It is responsible for the commissioning, producing, scheduling and broadcasting of all programming on the BBC's television channels, and is led by Danny Cohen.
Is there an answer to this question: What is responsible for scheduling all programs?

Answer: unanswerable


Question: Notably, a statute does not disappear automatically merely because it has been found unconstitutional; it must be deleted by a subsequent statute. Many federal and state statutes have remained on the books for decades after they were ruled to be unconstitutional. However, under the principle of stare decisis, no sensible lower court will enforce an unconstitutional statute, and any court that does so will be reversed by the Supreme Court. Conversely, any court that refuses to enforce a constitutional statute (where such constitutionality has been expressly established in prior cases) will risk reversal by the Supreme Court.
Is there an answer to this question: A statute is automatically removed when it is found to be what?

Answer: unanswerable


Question: In April 2008, a £90m contract was signed with Boeing for a "quick fix" solution, so they can fly by 2010: QinetiQ will downgrade the Chinooks—stripping out some of their more advanced equipment.
Is there an answer to this question: Which aircraft manufacturer got a contract with the MoD?

Answer:
Boeing