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．his common sense B．his sense of humour C．his sight D．his sixth sense
A．the human brain B．glands and systems in the body C．the cortex of the adrenal gland D．the medulla of the adrenal gland