汗马功劳的英文怎么说

[Literal Meaning] 

sweat/horse/contribution 

one's contributions as a soldier who rides a sweating horse 

[解释] 

古代指在战场上建立战功。现指辛勤工作做出的贡献。 

[Explanation] 

one's contributions in work 

[例子] 

在美国的华工为修筑铁路立下了汗马功劳，却受到了不公平的待遇。 

[Example] 

The Chinese labors in the US had made their contributions in building railway but were treated unfairly.