marginal profit的用法和样例：
例句
- Store productivity is declining, sales per square foot are falling and profit margins are shrinking.
店铺生产率不断下降，每平方英尺销售量在下跌，边际利润在萎缩。 - Regarding the cost, rational commercial banks may hope its marginal profit gained by the engagement in its reputation promotion equals to the banks' lose due to hacker's attack.
理性的商业银行出于成本的考虑，会希望在提高声誉过程中所获得的边际利润与因骇客进攻而导致的银行损失相等。
