lǎo / shī / yòng / gōng / qiú / guān / xì / lái / jiě / shì / wēi / guān / jīng / jì / xué / zhōng / de / jià / gé / biàn / huà老师用供求关系来解释微观经济学中的价格变化。The teacher used supply and demand to explain price changes in microeconomics.