In simple words, an Oxygen Concentrator works on electricity; takes in room air, removes Nitrogen from it and provides upto 95% pure Oxygen. The composition of air (78% Nitrogen, 21% Oxygen and 1% other gases like Carbon Dioxide, Argon, etc.) clearly shows that air is mainly comprised of two gases: Nitrogen and Oxygen [together 99%].
Word Origin and History for savoir-faire Expand. n. instinctive knowledge of the right course of action in any circumstance, 1815, from French, literally to know (how) to do, from savoir to know (from Latin sapere; see sapient) + faire (from Latin facere; see factitious).
Agnes of Sorrento Harriet Beecher Stowe. In Glasgow, show your savoir-faire; but, in Edinburgh and Aberdeen, your savoir-vivre. Friend Mac Donald Max O'Rell. Bindle, not to be outdone in savoir-faire, picked up the menu and regarded it with wrinkled brow. Adventures of Bindle Herbert George Jenkins. Determined that never again, even to herself, should she call me a boy, I summoned to my aid all the savoir-faire I could command.