Consider the example shown in Figure 2–1, with the “martini-glass” shape showing the net price of the factory product. Suppose all consumers switch to spring-loaded sneakers(装了弹簧的跑鞋), decreasing walking time per round-trip mile from 1 / 12 hours to 1 / 18 hours. Q1: The slope(斜率) of the net-price curve(净价格曲线) changes to_____and the width of the market area changes from 16 miles (8 on each side) to _____ miles (_____ on each side).