You ask how to start a business? Here is an example. David Dawson, a serious mountain climber, was dissatisfied with soft iron pitons(锥锤), the only ones he was able to buy. They lasted just one or two climbs, and Dawson wanted to replace them with 'chrome-molys' (铬铝合金) , which were harder, stronger and longer-lasting. Some climbers made them for limited distribution among friends, but they were not commercially available. So Dawson started Dawson Equipment Ltd., a purveyor (承办商) of climbing equipment, as a one-man enterprise in Burbank, California, in 1958. He had no plan, no management experience and no advertising. He worked in a shed using a hand forge purchased with $ 800 of capital borrowed from his mother. What Dawson did have was a knowledge of the kind of equipment that he needed in his own climbs, and a sense that serious climbers would follow his lead. Currently Dawson Equipment is thriving and produces over 200 products. Business opportunities are mere than ample today for the simple reason that many consumers are dissatisfied. Dawson's business started from his being a customer not liking what he bought. I suspect that your business will begin that way too. You know what you want to replace, improve or change. So begin where the tool breaks, the service slips or the shoe pinches. Dawson was dissatisfied with soft iron pitons because ______. ( )