Of course, the two had poured significant time into the business, but the marginal cost of getting the business off the ground was close to zero.
当然，这两个人投入了大量时间来经营生意，但使商业起步的边际成本接近于零。
2
Namely second is the marginal nature principle, select as far as possible at the edge of Central Plains like Xi 'an, Beijing and Nanjing etc ground as the capital.