Mike is a middle school student. He goes to school from Monday to Friday. His home is about 5 miles from school. He usually walks to school. It takes him 30 minutes to walk there. Nancy's home is a little farther. It's 20 miles from school. So she often takes the school bus. It takes her 15 minutes to get to school. Bob lives outside the city. It's a town 30 miles away from his school. He takes the subway. It takes him 8 minutes to get to school by subway. He can have breakfast at home and then leave for the subway station. He studies very hard.

①生产更符合消费者差异性需求的食盐品种，扩大食盐消费量

②打破国企对食盐的垄断经营，引入竞争机制，激发行业活力

③倒逼食盐企业转型升级，注重品牌建设，增强市场竞争力

④避免政府干预食盐产销，尊重市场对资源配置的决定作用