通常，当它们游泳时，会发出咔嚓的声音，所产生的声波会在回声中被反射回到它们身边。

Usually, as they swim, they make clicking noises, and the resulting sound waves are reflected in an echo and travel back to them.

youdao

通常，当它们游泳时，会发出咔嚓的声音，所产生的声波会在回声中被反射回到它们身边。

Usually, as they swim, they make clicking noises, and the resulting sound waves are reflected in an echo and travel back to them.

youdao