The lecture apparently disproves what is argued in the reading material. According to the passage … However the professor asserts that a closer scrutiny of this argument would reveal how flimsy it is. He then presents several evidences to demonstrate his statement.
To start with, the professor claims that the reading passage fails to take into account that…
Therefore, the assertion of the author seems too absolute since other possibilities could not be eliminated by any current evidence.
Furthermore, the passage assumes that…. The professor, however, suggests that this assumption may not be merited by the evidence. Say, ….. The contradiction is obvious here when … . On the basis of this point the lecture explicitly refutes the passage.
Last but not the least, the passage may be right about …., but one critical fact is being left out of consideration. Pointed out by the professor, the author totally neglects the truth that… On account of above-mentioned grave mistakes, the author’s assertion turned out to be a preposterous idea.
In conclusion, based on the arguments offered above, the professor clearly identifies the defects in the reading passage and forcefully shows that…
The reading passage concentrates on several theories about the cause of the odd sounds. However, in the lecture, the professor respectively points out the problems in all his assertions.
First, even though the reading passage suggests that the noises were caused by orcas during courtship ritual, the professor argues that orcas live in the surface of the water whereas the submarines dived to the deep ocean and thus cannot hear the sounds. Besides, the nearby whales could have been found by the sonar.
Second, despite the statement in the reading passage that the sounds were emitted by giant squid that approached the submarines with curiosity, the professor contends that squids have always lived in the ocean and therefore it’s unlikely that their sounds were first detected in 1960s but disappeared by 1980.
Third, the author asserts that the quackers were caused by a foreign submarine while the professor proves that this claim is indefensible by pointing out that submarines cannot move or change direction so quickly with no engine noise because even today we are technologically impossible to build that kind of submarines.