Starting in the 1960s and continuing until the 1980s, sailors in Russian submarines patrolling the North Alantic and Arctic Ocean would occasionally hear strange sounds. These underwater noises reminded the submarine crews of frog croaks, so they called the sounds “quackers” (from the Russian word for frog sounds). The sources of the sound seemed to be moving with great speed and agility; however, the submarines’ sonar (a method of detecting objects underwater) was unable to detect any solid moving objects in the area. There are several theories about what might have caused the odd sounds.
The first theory suggests that the strange noises were actually the calls of male and female ocra whales during a courtship ritual. Orca whales are known to inhabit the areas where the submarines were picking up the bizarre noises. Orcas have been studied extensively, and the sounds they make when trying to attract a male are similar to those that the submarines were detecting.
A second idea is that the sounds were caused by giant squid. Giant squids are gaint marine invertebrates that live deep in the ocean and prey on large fish. They are difficult to detect by sonar because they have soft bodies with no skeleton. Not much is known about giant squid behavior, but their complex brains suggest they are intelligent animals. It is possible they have the ability to emit sound, and perhaps they approached the submarines out of curiosity.
A third theory suggests the Russian submarines were picking up stray sounds from some military technology, like another country’s submarines that were secretly patrolling the area. Perhaps the foreign submarines did not register on sonar because they were using a kind of technology specifically designed to make them undetectable by sonar. The strange froglike sounds may have been emitted by the foreign submarines unintentionally.
There is a heated debate on the possible origin of strange sounds "quackers". The author in the reading passage explores three assumptions, while the professor, in the lecture, contradicts all these possibilities respectively by three specific points as supports.
First, the author asserts the strange noises were from orca whale because they need to emit special sounds to attract mates, while the professor contends this view by pointing out orca whale lives in the surface of ocean and their sound is not detectable for the submarine's sonar as submarines usually dive to the deep ocean. Besides, orca whale would be detected if they are near enough to the submarine.
Second, despite the statement in the reading passage that the sounds were caused by giant squid owing to their intelligence and their soft body, the professor argues that the sound has been suddenly disappeared since 1980, but giant squid is still living in that area. Thus, it is unlikely that their sound was first detected in 1960 and disappeared by 1980.
Third, even though the reading passage suggests the sounds might come from foreign undetectable submarines, the professor proves this claim is indefensible because even today human's submarines can not move or change direction so fast. Furthermore, submarines moving would cause a lot of noise, while strange sounds were quite silent and pure.
Grammar and spelling errors:
Line 5, column 264, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'submarines'' or 'submarine's'?
Suggestion: submarines'; submarine's
...d their sound is not detectable for the submarines sonar as submarines usually dive to the...
^^^^^^^^^^
Transition Words or Phrases used:
besides, but, first, furthermore, if, second, so, still, third, thus, while
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 12.0 10.4613686534 115% => OK
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 4.0 12.0772626932 33% => More relative clauses wanted.
Pronoun: 14.0 22.412803532 62% => OK
Preposition: 25.0 30.3222958057 82% => OK
Nominalization: 3.0 5.01324503311 60% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1178.0 1373.03311258 86% => OK
No of words: 222.0 270.72406181 82% => More content wanted.
Chars per words: 5.30630630631 5.08290768461 104% => OK
Fourth root words length: 3.8600083453 4.04702891845 95% => OK
Word Length SD: 2.77435061693 2.5805825403 108% => OK
Unique words: 136.0 145.348785872 94% => More unique words wanted.
Unique words percentage: 0.612612612613 0.540411800872 113% => OK
syllable_count: 351.9 419.366225166 84% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 1.0 3.25607064018 31% => OK
Article: 4.0 8.23620309051 49% => OK
Subordination: 4.0 1.25165562914 320% => Less adverbial clause wanted.
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 2.0 2.5761589404 78% => OK
Performance on sentences:
How many sentences: 8.0 13.0662251656 61% => Need more sentences. Double check the format of sentences, make sure there is a space between two sentences, or have enough periods. And also check the lengths of sentences, maybe they are too long.
Sentence length: 27.0 21.2450331126 127% => The Avg. Sentence Length is relatively long.
Sentence length SD: 89.1806453217 49.2860985944 181% => OK
Chars per sentence: 147.25 110.228320801 134% => OK
Words per sentence: 27.75 21.698381199 128% => OK
Discourse Markers: 9.375 7.06452816374 133% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 2.0 4.33554083885 46% => More positive sentences wanted.
Sentences with negative sentiment : 4.0 4.45695364238 90% => OK
Sentences with neutral sentiment: 2.0 4.27373068433 47% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.112065100507 0.272083759551 41% => OK
Sentence topic coherence: 0.0502250966244 0.0996497079465 50% => OK
Sentence topic coherence SD: 0.0453252949914 0.0662205650399 68% => OK
Paragraph topic coherence: 0.0662613790166 0.162205337803 41% => OK
Paragraph topic coherence SD: 0.052849449884 0.0443174109184 119% => OK
Essay readability:
automated_readability_index: 17.5 13.3589403974 131% => OK
flesch_reading_ease: 44.07 53.8541721854 82% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 13.8 11.0289183223 125% => OK
coleman_liau_index: 13.81 12.2367328918 113% => OK
dale_chall_readability_score: 8.6 8.42419426049 102% => OK
difficult_words: 51.0 63.6247240618 80% => More difficult words wanted.
linsear_write_formula: 14.0 10.7273730684 131% => OK
gunning_fog: 12.8 10.498013245 122% => OK
text_standard: 14.0 11.2008830022 125% => OK
What are above readability scores?
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Rates: 90.0 out of 100
Scores by essay e-grader: 27.0 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.