English Fluid Cited by user Wotheina on 22 Jun 2021 In physics, a fluid is a liquid, gas, or other material that continuously deforms (flows) under an applied shear stress, or external force.
English Upper respiratory tract infection Cited by user ShelleyAdams on 19 Dec 2016 In 2013, 18.8 million cases of upper respiratory infections occurred. As of 2014, upper respiratory infections caused about 3,000 deaths down from 4,000 in 1990.