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 European 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 off 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 ecosystems 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 depend 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.
<p style="padding: 10px 20px 0px; margin-bottom: 0px; line-height: 24px; font-size: 16px; color: rgb(58, 58, 58); font-family: "Helvetica Neue", Helvetica, STHeiTi, Arial, "Microsoft YaHei", sans-serif; white-space: normal;">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 European 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.</p><p style="padding: 10px 20px 0px; margin-bottom: 0px; line-height: 24px; font-size: 16px; color: rgb(58, 58, 58); font-family: "Helvetica Neue", Helvetica, STHeiTi, Arial, "Microsoft YaHei", sans-serif; white-space: normal;">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 off 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.</p><p style="padding: 10px 20px 0px; margin-bottom: 0px; line-height: 24px; font-size: 16px; color: rgb(58, 58, 58); font-family: "Helvetica Neue", Helvetica, STHeiTi, Arial, "Microsoft YaHei", sans-serif; white-space: normal;">Second, the sea cow population may have become extinct because of ecosystems 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 depend on.</p><p style="padding: 10px 20px 0px; margin-bottom: 0px; line-height: 24px; font-size: 16px; color: rgb(58, 58, 58); font-family: "Helvetica Neue", Helvetica, STHeiTi, Arial, "Microsoft YaHei", sans-serif; white-space: normal;">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.</p>
Grammar and spelling errors:
Line 1, column 2381, Rule ID: ENGLISH_WORD_REPEAT_BEGINNING_RULE
Message: Three successive sentences begin with the same word. Reword the sentence or use a thesaurus to find a synonym.
...raders caught the last sea cow in 1768. It thus seems reasonable to believe that h...
^^
Line 1, column 2511, Rule ID: LARGE_NUMBER_OF[1]
Message: Specify a number, remove phrase, or simply use 'many' or 'numerous'
Suggestion: many; numerous
...apons that allowed them to quickly kill a large number of the animals, was the main cause of the ...
^^^^^^^^^^^^^^^^^
Transition Words or Phrases used:
but, first, if, may, second, so, then, third, thus
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 13.0 10.4613686534 124% => OK
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 1.0 7.30242825607 14% => More conjunction wanted.
Relative clauses : 9.0 12.0772626932 75% => More relative clauses wanted.
Pronoun: 13.0 22.412803532 58% => OK
Preposition: 41.0 30.3222958057 135% => OK
Nominalization: 8.0 5.01324503311 160% => OK
Performance on vocabulary words:
No of characters: 2226.0 1373.03311258 162% => OK
No of words: 374.0 270.72406181 138% => Less content wanted.
Chars per words: 5.95187165775 5.08290768461 117% => OK
Fourth root words length: 4.3976220399 4.04702891845 109% => OK
Word Length SD: 3.98692062201 2.5805825403 154% => OK
Unique words: 172.0 145.348785872 118% => OK
Unique words percentage: 0.459893048128 0.540411800872 85% => More unique words wanted or less content wanted.
syllable_count: 595.8 419.366225166 142% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 4.0 3.25607064018 123% => OK
Article: 5.0 8.23620309051 61% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 1.0 2.5761589404 39% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 12.0 13.0662251656 92% => OK
Sentence length: 31.0 21.2450331126 146% => The Avg. Sentence Length is relatively long.
Sentence length SD: 189.601995418 49.2860985944 385% => The lengths of sentences changed so frequently.
Chars per sentence: 185.5 110.228320801 168% => OK
Words per sentence: 31.1666666667 21.698381199 144% => OK
Discourse Markers: 4.16666666667 7.06452816374 59% => More transition words/phrases wanted.
Paragraphs: 1.0 4.09492273731 24% => More paragraphs wanted.
Language errors: 2.0 4.19205298013 48% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 3.0 4.45695364238 67% => OK
Sentences with neutral sentiment: 6.0 4.27373068433 140% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.240003608744 0.272083759551 88% => OK
Sentence topic coherence: 0.140331176126 0.0996497079465 141% => OK
Sentence topic coherence SD: 0.131306573682 0.0662205650399 198% => OK
Paragraph topic coherence: 0.240003608744 0.162205337803 148% => OK
Paragraph topic coherence SD: 0.0 0.0443174109184 0% => Paragraphs are similar to each other. Some content may get duplicated or it is not exactly right on the topic.
Essay readability:
automated_readability_index: 22.2 13.3589403974 166% => OK
flesch_reading_ease: 40.01 53.8541721854 74% => OK
smog_index: 13.0 5.55761589404 234% => Smog_index is high.
flesch_kincaid_grade: 15.4 11.0289183223 140% => OK
coleman_liau_index: 17.82 12.2367328918 146% => OK
dale_chall_readability_score: 8.17 8.42419426049 97% => OK
difficult_words: 71.0 63.6247240618 112% => OK
linsear_write_formula: 9.0 10.7273730684 84% => OK
gunning_fog: 14.4 10.498013245 137% => OK
text_standard: 9.0 11.2008830022 80% => OK
What are above readability scores?
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Write the essay in 20 minutes.
Minimum four paragraphs wanted. The correct pattern:
para 1: introduction
para 2: doubt 1
para 3: doubt 2
para 4: doubt 3
Less contents wanted from the reading passages(25%), more content wanted from the lecture (75%).
Don't need a conclusion paragraph.
Read sample essays from ETS:
http://www.testbig.com/users/toeflwritingmaster
Rates: 73.3333333333 out of 100
Scores by essay e-grader: 22.0 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.