单项选择题
A．products should be made with less cost but higher efficiency B．products should be sold at low prices in large quantity C．products should be sold at high prices in large quantity D．standards must be established in his plants
A．through great social revolution B．through automotive technological revolution C．through numerous mechanical inventions D．through radical political reforms
A．the brain system. B．functions of kidneys C．other human organs related to the kidneys D．reactions of the body to stress and danger