So labor costs per ton of guano will rise in real terms unless technological advances allow more efficient use of labor. 所以每吨海鸟粪的人工成本以真实方式计会上升，除非技术进步允许更有效率的运用人工。
The higher labor costs for milling and weaving in Europe, where more traditional manufacturing methods are employed, account for the higher purchase price. 欧洲采用较传统的生产方式，加工与纺织的人工成本因而较昂贵，售价也较高。
