A huge marine mammal known as Steller’s sea cow once lived in the waters around Bering Island off the coast of Siberia. It was described in 1741 by Georg W. Steller, a naturalist who was among the first Europeans to see one. In 1768 the animal became extinct. The reasons for the extinction are not clear. Here are three theories about the main cause of the extinction.
First, the sea cows may have been overhunted by groups of native Siberian people. If this theory is correct, then the sea cow population would have originally been quite large, but hundreds of years of too much hunting by the native people diminished the number of sea cows. Sea cows were a good source of food in a harsh environment, so overhunting by native people could have been the main cause of extinction.
Second, the sea cow population may have become extinct because of ecosystem disturbances that caused a decline in their main source of food, kelp (a type of sea plant). Kelp populations respond negatively to a number of ecological changes. It is possible that ecological changes near Bering Island some time before 1768 caused a decrease of the kelp that the sea cows depended on.
Third, the main cause of extinction of the sea cows could have been European fur traders who came to the island after 1741. It is recorded that the fur traders caught the last sea cow in 1768. It thus seems reasonable to believe that hunting by European fur traders, who possessed weapons that allowed them to quickly kill a large number of the animals, was the main cause of the sea cow’s extinction.
Both the reading and the listening discuss about the possilbe cause of cow's extinction. The former argues that there may be three possible reasons, but the later contradicts each of these points.
First of all,t the author of the passage claims that perhaps the cow's were extinct because of overhunting by the Siberian people. However, the lecturer contends that since the Sea cow's are massive, their weight is approximately ten ton, and since the native Siberian population were low, that ecosystem disturbances led a decline in cow's population.
Third of all, the the author of the passage claims that European fur traders may have been the main cause of extinction of sea cows. Nonetheless, listening contends that even when the European came , the number of cow's population were declining. So it should be considered that there were something causing in decline of cow's population.even a single Cow can feed them for a month. So it is unlikey that it was extinct because of the overhunting.
Second of all, the writer of the passage claims that ecosystem disturbances might be a possible cause of the decline in Steller's sea cow population. Nonetheless, the audio argue that if the ecosystem disturbances were happened before 1768, it would have caused a decline in other sea creatires like Whales, but there were no decline in other sea species reported. So it doesn't hold water to say that disturbances in ecosystem led a decline in cow's population.
Grammar and spelling errors:
Line 3, column 13, Rule ID: COMMA_PARENTHESIS_WHITESPACE
Message: Put a space after the comma
Suggestion: , t
...s each of these points. First of all,t the author of the passage claims that p...
^^
Line 3, column 288, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...the native Siberian population were low, that ecosystem disturbances led a declin...
^^
Line 5, column 15, Rule ID: ENGLISH_WORD_REPEAT_RULE
Message: Possible typo: you repeated a word
Suggestion: the
...e in cows population. Third of all, the the author of the passage claims that Europ...
^^^^^^^
Line 5, column 15, Rule ID: DT_DT[1]
Message: Maybe you need to remove one determiner so that only 'the' or 'the' is left.
Suggestion: the; the
...e in cows population. Third of all, the the author of the passage claims that Europ...
^^^^^^^
Line 5, column 198, Rule ID: COMMA_PARENTHESIS_WHITESPACE
Message: Put a space after the comma, but not before the comma
Suggestion: ,
...ontends that even when the European came , the number of cows population were decl...
^^
Line 7, column 371, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: doesn't
...ne in other sea species reported. So it doesnt hold water to say that disturbances in ...
^^^^^^
Transition Words or Phrases used:
but, first, however, if, may, nonetheless, second, so, third, first of all
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 14.0 10.4613686534 134% => OK
Auxiliary verbs: 6.0 5.04856512141 119% => OK
Conjunction : 4.0 7.30242825607 55% => More conjunction wanted.
Relative clauses : 12.0 12.0772626932 99% => OK
Pronoun: 19.0 22.412803532 85% => OK
Preposition: 29.0 30.3222958057 96% => OK
Nominalization: 8.0 5.01324503311 160% => OK
Performance on vocabulary words:
No of characters: 1222.0 1373.03311258 89% => OK
No of words: 242.0 270.72406181 89% => More content wanted.
Chars per words: 5.04958677686 5.08290768461 99% => OK
Fourth root words length: 3.94415379849 4.04702891845 97% => OK
Word Length SD: 2.81449592687 2.5805825403 109% => OK
Unique words: 121.0 145.348785872 83% => More unique words wanted.
Unique words percentage: 0.5 0.540411800872 93% => More unique words wanted or less content wanted.
syllable_count: 381.6 419.366225166 91% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 3.0 3.25607064018 92% => OK
Article: 6.0 8.23620309051 73% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 3.0 1.51434878587 198% => OK
Preposition: 0.0 2.5761589404 0% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 11.0 13.0662251656 84% => 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: 22.0 21.2450331126 104% => OK
Sentence length SD: 46.4930457788 49.2860985944 94% => OK
Chars per sentence: 111.090909091 110.228320801 101% => OK
Words per sentence: 22.0 21.698381199 101% => OK
Discourse Markers: 6.72727272727 7.06452816374 95% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 6.0 4.19205298013 143% => OK
Sentences with positive sentiment : 1.0 4.33554083885 23% => More positive sentences wanted.
Sentences with negative sentiment : 5.0 4.45695364238 112% => OK
Sentences with neutral sentiment: 5.0 4.27373068433 117% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.124650282272 0.272083759551 46% => OK
Sentence topic coherence: 0.0560673461053 0.0996497079465 56% => OK
Sentence topic coherence SD: 0.0294996664684 0.0662205650399 45% => Sentences are similar to each other.
Paragraph topic coherence: 0.0740566140148 0.162205337803 46% => OK
Paragraph topic coherence SD: 0.0345718835424 0.0443174109184 78% => OK
Essay readability:
automated_readability_index: 13.4 13.3589403974 100% => OK
flesch_reading_ease: 49.15 53.8541721854 91% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 11.9 11.0289183223 108% => OK
coleman_liau_index: 12.01 12.2367328918 98% => OK
dale_chall_readability_score: 7.66 8.42419426049 91% => OK
difficult_words: 45.0 63.6247240618 71% => More difficult words wanted.
linsear_write_formula: 11.0 10.7273730684 103% => OK
gunning_fog: 10.8 10.498013245 103% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
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Rates: 71.6666666667 out of 100
Scores by essay e-grader: 21.5 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.