TPO32

The article states that from 1960's to 1980's, there was a curious submarine sounds which were heard by sailors in Russian submarines. The Russian sailors called these sounds "Quakers'' due to the sounds' similarity with frog croaks. The author provides three hypothesis about the noises' resource and provides three reasons. However, the professor explains that these reasons are not convincing and refutes each of them.
First of all, the reading claims that these sounds might be from a conversation between male and female orca whales because the sounds were listened near the place where whales are living. The professor refutes this opinion by saying that it is impossible for submarines to hear the whales sound because the Orcas live near the ocean’s surface, while submarines are at the deep parts of the ocean.
Secondly, the article posits that the sounds might be caused by giant marine invertebrates that live in deep parts of the ocean named giant squids. This specie's brilliant brain makes the hypothesis about their ability to make that sounds. However, the professor says that the giant squids have lived before the sounds were heard, and they also live in that inhabitant now. So, the submarine noise were stopped suddenly after 20 years of their beginning. Therefore, giant squids cannot be the source of these noises.
Third, the reading says that they would be from a foreign submarine which uses a technology to be undetectable. The professor opposes this point by explaining that while the sounds move fast and change their direction very quickly, they could not be from a submarine. Submarines move slowly and make a lot of engine noise under water. But there is no engine sound has been heard. Also human has not invented a submarine, which moves as fast as the noises, yet.