Article: DST's clock shifts have the obvious disadvantage of complexity. People must remember to change their clocks; this can be time-consuming, particularly for mechanical clocks that cannot be moved backward safely. People who work across time zone boundaries need to keep track of multiple DST rules, as not all locations observe DST or observe it the same way. The length of the calendar day becomes variable; it is no longer always 24 hours. Disruption to meetings, travel, broadcasts, billing systems, and records management is common, and can be expensive. During an autumn transition from 02:00 to 01:00, a clock reads times from 01:00:00 through 01:59:59 twice, possibly leading to confusion.

Question: What do people often have trouble remembering to do for DST?
Ans: change their clocks


Article: Many of the instruments used to perform medieval music still exist, but in different forms. Medieval instruments included the wood flute (which in the 21st century is made of metal), the recorder and plucked string instruments like the lute. As well, early versions of the organ, fiddle (or vielle), and trombone (called the sackbut) existed. Medieval instruments in Europe had most commonly been used singly, often self accompanied with a drone note, or occasionally in parts. From at least as early as the 13th century through the 15th century there was a division of instruments into haut (loud, shrill, outdoor instruments) and bas (quieter, more intimate instruments).

Question: Medieval instrument in Europe were commonly used how?
Ans: singly


Article: In its Basic Laws, Israel defines itself as a Jewish and democratic state. Israel is a representative democracy with a parliamentary system, proportional representation and universal suffrage. The prime minister serves as head of government and the Knesset serves as the legislature. Israel is a developed country and an OECD member, with the 35th-largest economy in the world by nominal gross domestic product as of 2015[update]. The country benefits from a highly skilled workforce and is among the most educated countries in the world with the one of the highest percentage of its citizens holding a tertiary education degree. The country has the highest standard of living in the Middle East and the fourth highest in Asia, and has one of the highest life expectancies in the world.

Question: Where is Israel's standard of living ranked in Asia?
Ans: fourth


Article: Manifold vacuum can be used to drive accessories on automobiles. The best-known application is the vacuum servo, used to provide power assistance for the brakes. Obsolete applications include vacuum-driven windscreen wipers and Autovac fuel pumps. Some aircraft instruments (Attitude Indicator (AI) and the Heading Indicator (HI)) are typically vacuum-powered, as protection against loss of all (electrically powered) instruments, since early aircraft often did not have electrical systems, and since there are two readily available sources of vacuum on a moving aircraft—the engine and an external venturi. Vacuum induction melting uses electromagnetic induction within a vacuum.

Question: Why are the Attitude indicator and heading indicator vacuum-powered?
Ans:
protection against loss of all (electrically powered) instruments,