The zebra mussel, a freshwater shellfish native to Eastern Europe, has long been spreading out from its original habitats and has now reached parts of North America. There are reasons to believe that this invasion cannot be stopped and that it poses a serious threat to freshwater fish populations in all of North America.
First, the history of the zebra mussel's spread suggests that the invasion might be unstoppable. It is a prime example of an invasion made possible by human transportation. From the zebra mussel's original habitats in Eastern Europe, ships helped spread it out along new canals built to connect Europe's waterways. The mussel can attach itself to a ship's bottom or can survive in the water - called "ballast water" - that the ship needs to take on to properly balance its cargo. By the early nineteenth century, the mussel had spread to the whole of Europe. It was later carried to the east coast of North America in the ballast water of ships traveling from Europe. The way ships have spread the zebra mussel in the past strongly suggests that the species will soon colonize all of North America.
Moreover, once zebra mussels are carried to a new habitat, they can dominate it. They are a hardy species that does well under a variety of conditions, and they have a high rate of reproduction. Most important, however, zebra mussels often have no predators in their new habitats, and species without natural predators are likely to dominate their habitats.
Finally, zebra mussels are likely to cause a decline in the overall fish population in habitats where they become dominant. The mussels are plankton eaters, which means that they compete for food with many freshwater fish species.
The article states that the spreading of The zebra mussel is unstoppable and provides three reasons for supports. However, the professor explains that there are ways to control the spread of the zebra mussel in North America and refutes each of the author's reasons.
First, the reading claims that the history of the zebra mussel's invasion strongly suggests that the spreading of mussels is uncontrollable and this species will dominant the freshwater in North America. The professor refutes this point by saying that in the past, people did not know the best ways to control the spread of mussels. He states that ships can be refilled from seawater and salty water will immediately kill mussels.
Second, the article posits that many conditions in new habitats will help mussels to spread, as a high rate of reproduction and a lake of natural predators. However, the professor says that this argument in the passage is unlikely. According to the professor, birds are one of the mussel's predators; therefore, mussels are unlikely to dominant the new habitat.
Third, the reading says that zebra mussels will decline the population of overall fish species in a new habitat because mussels will compete for food with other fish species. The professor opposes this point by explaining that mussels have positive impacts on other fish species. He states that mussels generate nutrients for fish living in the bottom of rivers.
Transition Words or Phrases used:
first, however, second, so, third, well
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 8.0 10.4613686534 76% => OK
Auxiliary verbs: 8.0 5.04856512141 158% => OK
Conjunction : 5.0 7.30242825607 68% => OK
Relative clauses : 12.0 12.0772626932 99% => OK
Pronoun: 18.0 22.412803532 80% => OK
Preposition: 28.0 30.3222958057 92% => 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: 1216.0 1373.03311258 89% => OK
No of words: 240.0 270.72406181 89% => More content wanted.
Chars per words: 5.06666666667 5.08290768461 100% => OK
Fourth root words length: 3.93597934253 4.04702891845 97% => OK
Word Length SD: 2.4100340016 2.5805825403 93% => OK
Unique words: 123.0 145.348785872 85% => More unique words wanted.
Unique words percentage: 0.5125 0.540411800872 95% => More unique words wanted or less content wanted.
syllable_count: 363.6 419.366225166 87% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 8.0 8.23620309051 97% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 1.0 2.5761589404 39% => 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: 21.0 21.2450331126 99% => OK
Sentence length SD: 36.3595452244 49.2860985944 74% => OK
Chars per sentence: 110.545454545 110.228320801 100% => OK
Words per sentence: 21.8181818182 21.698381199 101% => OK
Discourse Markers: 3.54545454545 7.06452816374 50% => More transition words/phrases wanted.
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 0.0 4.19205298013 0% => OK
Sentences with positive sentiment : 4.0 4.33554083885 92% => OK
Sentences with negative sentiment : 3.0 4.45695364238 67% => OK
Sentences with neutral sentiment: 4.0 4.27373068433 94% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.235545582278 0.272083759551 87% => OK
Sentence topic coherence: 0.0980802756021 0.0996497079465 98% => OK
Sentence topic coherence SD: 0.0758980887721 0.0662205650399 115% => OK
Paragraph topic coherence: 0.159511281321 0.162205337803 98% => OK
Paragraph topic coherence SD: 0.0684345477678 0.0443174109184 154% => OK
Essay readability:
automated_readability_index: 13.4 13.3589403974 100% => OK
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: 12.13 12.2367328918 99% => OK
dale_chall_readability_score: 8.49 8.42419426049 101% => OK
difficult_words: 58.0 63.6247240618 91% => OK
linsear_write_formula: 13.5 10.7273730684 126% => OK
gunning_fog: 10.4 10.498013245 99% => OK
text_standard: 14.0 11.2008830022 125% => OK
What are above readability scores?
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Rates: 68.3333333333 out of 100
Scores by essay e-grader: 20.5 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.