When I was a little girl, many people around me enjoyed bargaining over price. I could not understand why they got so much pleasure from bargaining when they were making purchases. My mother told me that customers were in eager .
In the very beginning shortly after the invention of eyeglasses, they were regarded as merely optical instruments to improve eyesight during the11th century; later Benjamin Franklin invented bifocal eyeglasses, which were an important breakthrough of the optical industry; and now . |