"那是牛的声音" 的英文翻译是 "that is the sound of a cow". 来源是牛在叫，叫声听起来像 "moo".
例句：
Listen, do you hear that? That is the sound of a cow.
John: What is that noise?
Mary: That is the sound of a cow. It is coming from the farm next door.
中文翻译：
听，你听到了吗？那是牛的声音。
约翰：那是什么声音？
玛丽：那是牛的声音。它来自隔壁的农场。