阅读材料
At the end of the Triassic period 200 million years ago, there was a mass-extinction event that caused the extinction of more than half of all living species. It was this extinction event that allowed dinosaurs to become the dominant species for the next 145 million years. We do not know exactly what happened that eliminated so many species in a relatively short period of time, but there are several possible explanations.
One theory involves the decline of sea levels. Near the end of the Triassic period, sea levels were fluctuating. When sea levels fall, the habitats for ocean populations that live in the shallows and land species that live on the coast are destroyed. The destruction of coastal and shallow-ocean species would have had a profound effect on food chains worldwide, leading to mass extinctions.
Another theory involves massive climate cooling. The end of the Triassic period was marked by widespread volcanic activity. The volcanoes released large amounts of sulfur dioxide (SO2). A rise in atmospheric SO2 is known to cause a lowering in global temperatures. Such climate change could have devastated many species and led to the extinctions.
The third theory involves an asteroid strike. Asteroids (objects from outer space) occasionally collide with Earth. When an asteroid hits Earth’s surface, it often displaces large amounts of soil and crushed rock, leaving behind a depression, or crater. The displaced debris is thrown up into the atmosphere where it can block out sunlight for many months or even a few years. A sufficiently massive asteroid impact at the end of the Triassic period may have blocked sunlight long enough for most plants to die and many animal species to then starve.
The fact that there was a mass extinction at the end of the Triassic period 200 million years ago has always been a puzzle as to why it happened. While in reading passage, the author suggested that there are three possible explantations about how the mass-extinction occur, the speakers refuted it with three disagreements.
First of all, one proposed theory is that sea levels declined, leading many shallows and land species perished and eventually cause a catastrophe to the entire food chains. The speaker, though agree that sea levels did fluctuate, indicated that this would take million years to occur. The decline of sea level would not just happen suddenly, and because of that, some may have been adapting to that subtle change.
Secondly, another theory claimed that there were massive climate cooling due to the rising SO2 released from the volcanic activity at that time. Yet, according to the speaker, the rise in atmospheric SO2 would cool down the temperature, its effect is rather tentative. Only if the SO2 keep its presence in the atmosphere will it do the effect of cooling. However, most of the SO2 would combine with water, leaving a low density in the atmosphere. Thus, the speaker believed that it's not likely to cause the huge extinction due to its short efficacy.
Lastly, in the lecture, it is argued that few scientists believe there was once an asteroid strike. However true the asteroid may destroy the earth by blocking the sunlight from its debris in the atmosphere, there were no such craters found in the world to prove this theory. They did find one crater, although it was dated 12 million years earlier to the mass extinction.
Grammar and spelling errors:
Line 3, column 262, Rule ID: NODT_DOZEN[1]
Message: Use simply: 'a million'.
Suggestion: a million
...uctuate, indicated that this would take million years to occur. The decline of sea leve...
^^^^^^^
Transition Words or Phrases used:
first, however, if, lastly, may, second, secondly, so, thus, while, as to, first of all
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 11.0 10.4613686534 105% => OK
Auxiliary verbs: 7.0 5.04856512141 139% => OK
Conjunction : 3.0 7.30242825607 41% => More conjunction wanted.
Relative clauses : 11.0 12.0772626932 91% => OK
Pronoun: 24.0 22.412803532 107% => OK
Preposition: 32.0 30.3222958057 106% => OK
Nominalization: 5.0 5.01324503311 100% => OK
Performance on vocabulary words:
No of characters: 1391.0 1373.03311258 101% => OK
No of words: 282.0 270.72406181 104% => OK
Chars per words: 4.93262411348 5.08290768461 97% => OK
Fourth root words length: 4.09790868904 4.04702891845 101% => OK
Word Length SD: 2.55963774489 2.5805825403 99% => OK
Unique words: 173.0 145.348785872 119% => OK
Unique words percentage: 0.613475177305 0.540411800872 114% => OK
syllable_count: 421.2 419.366225166 100% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 3.0 3.25607064018 92% => OK
Article: 7.0 8.23620309051 85% => OK
Subordination: 3.0 1.25165562914 240% => Less adverbial clause wanted.
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 2.0 2.5761589404 78% => OK
Performance on sentences:
How many sentences: 13.0 13.0662251656 99% => OK
Sentence length: 21.0 21.2450331126 99% => OK
Sentence length SD: 31.7978079703 49.2860985944 65% => OK
Chars per sentence: 107.0 110.228320801 97% => OK
Words per sentence: 21.6923076923 21.698381199 100% => OK
Discourse Markers: 6.69230769231 7.06452816374 95% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
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: 0.202054907878 0.272083759551 74% => OK
Sentence topic coherence: 0.0664654348274 0.0996497079465 67% => OK
Sentence topic coherence SD: 0.0932435074657 0.0662205650399 141% => OK
Paragraph topic coherence: 0.120578227412 0.162205337803 74% => OK
Paragraph topic coherence SD: 0.0922920035638 0.0443174109184 208% => More connections among paragraphs wanted.
Essay readability:
automated_readability_index: 12.6 13.3589403974 94% => Automated_readability_index is low.
flesch_reading_ease: 58.62 53.8541721854 109% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 10.3 11.0289183223 93% => OK
coleman_liau_index: 11.31 12.2367328918 92% => OK
dale_chall_readability_score: 8.71 8.42419426049 103% => OK
difficult_words: 72.0 63.6247240618 113% => OK
linsear_write_formula: 14.0 10.7273730684 131% => OK
gunning_fog: 10.4 10.498013245 99% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
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Rates: 70.0 out of 100
Scores by essay e-grader: 21.0 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.