Face masks may be the key determinant of the Covid-19 curve, study suggests2020-06-172020-06-16http://sfl2000.com/wp-content/uploads/2015/01/SFL-New-Main-logo-2.pngStephen Frederick Logisticshttps://sfl2000.com/wp-content/uploads/2020/04/face-mask-toilet-paper.jpg200px200px