TPO 32

The professor rejects all the theories about the source of quackers and she says that researchers still debate about the source of the sound.

First, the passage suggests that the odd sounds could be from orca whales. The professor opposes this theory and she says orca whales lived in the areas where submarines roaming, however, they lived mostly near the surface of the water.In contrast, submarines moved deep down the water. Consequently, the sounds were not from whales.

Second, the professor refutes the theory which states that these sound made by giant squids in the passage. She declares that odd sounds just heard about two decades and after that they were disappeared. While, there are squids now living in the area. So, the noises were not made by squids.

Finally, the last theory mentions in the passage is that the noise could be from other submarines from other countries. The professor rejects this idea. She adds that the source of the sound seemed to be moving around and change direction quickly while, submarines could not move and change the direction that fast. And also the noises were not from the engine of submarines because there are not submarines which manufactured with no sound from the engine.