But no such noise accompanied the quackers.

但是没有这样的噪音伴随着嘎嘎声。

Russian submarines first detected quacker sound in the 1960s and reports of them continued for about two decades.

俄罗斯潜艇在 1960 年代首次探测到嘎嘎声， 有关它们的报道持续了大约二十年。

Third, the idea that the quackers were caused by a secret submarine from another country does not hold up.

第三， 认为嘎嘎声是由来自另一个国家的秘密潜艇造成的想法是站不住脚的。