Question: Question: "What is a sign of an efficient light source?"  Context: "An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in lumen per watt. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb" to the surroundings. The more transparent the lighting fixture is, the higher efficacy. Shading the light will normally decrease efficacy but increase the directionality and the visual comfort probability."  Answer:
Answer: more transparent

Question: Question: "Why are some of the Washington coins as expensive as $850 each?"  Context: "Early releases of the Washington coin included error coins shipped primarily from the Philadelphia mint to Florida and Tennessee banks. Highly sought after by collectors, and trading for as much as $850 each within a week of discovery, the error coins were identified by the absence of the edge impressions "E PLURIBUS UNUM IN GOD WE TRUST 2007 P". The mint of origin is generally accepted to be mostly Philadelphia, although identifying the source mint is impossible without opening a mint pack also containing marked units. Edge lettering is minted in both orientations with respect to "heads", some amateur collectors were initially duped into buying "upside down lettering error" coins. Some cynics also erroneously point out that the Federal Reserve makes more profit from dollar bills than dollar coins because they wear out in a few years, whereas coins are more permanent. The fallacy of this argument arises because new notes printed to replace worn out notes, which have been withdrawn from circulation, bring in no net revenue to the government to offset the costs of printing new notes and destroying the old ones. As most vending machines are incapable of making change in banknotes, they commonly accept only $1 bills, though a few will give change in dollar coins."  Answer:
Answer: coin included error coins

Question: Question: "What would allow one to live in accordance with Nature according to the philosophy of which Sphairos of Borysthenes and Antigonus II were both adherents?"  Context: "The Epicureans and the Cynics rejected public offices and civic service, which amounted to a rejection of the polis itself, the defining institution of the Greek world. Epicurus promoted atomism and an asceticism based on freedom from pain as its ultimate goal. Cynics such as Diogenes of Sinope rejected all material possessions and social conventions (nomos) as unnatural and useless. The Cyrenaics meanwhile, embraced hedonism, arguing that pleasure was the only true good. Stoicism, founded by Zeno of Citium, taught that virtue was sufficient for eudaimonia as it would allow one to live in accordance with Nature or Logos. Zeno became extremely popular, the Athenians set up a gold statue of him and Antigonus II Gonatas invited him to the Macedonian court. The philosophical schools of Aristotle (the Peripatetics of the Lyceum) and Plato (Platonism at the Academy) also remained influential. The academy would eventually turn to Academic Skepticism under Arcesilaus until it was rejected by Antiochus of Ascalon (c. 90 BCE) in favor of Neoplatonism. Hellenistic philosophy, had a significant influence on the Greek ruling elite. Examples include Athenian statesman Demetrius of Phaleron, who had studied in the lyceum; the Spartan king Cleomenes III who was a student of the Stoic Sphairos of Borysthenes and Antigonus II who was also a well known Stoic. This can also be said of the Roman upper classes, were Stoicism was dominant, as seen in the Meditations of the Roman emperor Marcus Aurelius and the works of Cicero."  Answer:
Answer:
virtue