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 inthe past strongly suggests that the species will soon colonize all of North America.
Moreover, once zebra mussels are carried to a new habitat, theycan 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.
Both of the reading and listening discuss about whether or not the number of the zebra mussels is controllable. The reading claim that this practice is not feasible. In contrast, the professor says that there are some ways to decline the number of the zebra mussel.
Firstly, the reading passage states that the human activity cause the zebra mussels increase due to the fact that some ships carry these kinds of specious from one point to another point. also it says that according to experience in this respect, this action is impossible. However, the professor says that due to the lack of knowledge, the people were not able to decline the number of the zebra mussels but at the moment the technology is able to control this action. Furthermore, he adds that we can kill the zebra mussels that are carried on the ships by some new methods.
Secondly, the reading passage declares that these animals can dominate the new places and they are so reproducible. In contrast, the professor says that perhaps there are not some predators for those in the local areas but totally there are a lot of predators for these animals. Therefore, from this way, these are controllable.
Finally, the reading passage state that the zebra mussels eat others fish and themselves become dominate in that area. In contrast, the professor casts doubt this point by saying that although these animal by eating fish have negative impact, they have positive effect on that area by producing some nutrients. these produced nutrients by the zebra mussels engender the number of fish to increase, so to speak, they can take a balance between fish.
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Grammar and spelling errors:
Line 1, column 49, Rule ID: WHETHER[7]
Message: Perhaps you can shorten this phrase to just 'whether'. It is correct though if you mean 'regardless of whether'.
Suggestion: whether
...the reading and listening discuss about whether or not the number of the zebra mussels is cont...
^^^^^^^^^^^^^^
Line 3, column 189, Rule ID: UPPERCASE_SENTENCE_START
Message: This sentence does not start with an uppercase letter
Suggestion: Also
...ecious from one point to another point. also it says that according to experience in...
^^^^
Line 3, column 189, Rule ID: SENT_START_CONJUNCTIVE_LINKING_ADVERB_COMMA[1]
Message: Did you forget a comma after a conjunctive/linking adverb?
Suggestion: also,
...ecious from one point to another point. also it says that according to experience in...
^^^^
Line 7, column 312, Rule ID: UPPERCASE_SENTENCE_START
Message: This sentence does not start with an uppercase letter
Suggestion: These
... that area by producing some nutrients. these produced nutrients by the zebra mussels...
^^^^^
Transition Words or Phrases used:
also, but, finally, first, firstly, furthermore, however, second, secondly, so, therefore, in contrast, so to speak
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 11.0 10.4613686534 105% => OK
Auxiliary verbs: 3.0 5.04856512141 59% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 14.0 12.0772626932 116% => OK
Pronoun: 34.0 22.412803532 152% => Less pronouns wanted
Preposition: 35.0 30.3222958057 115% => OK
Nominalization: 2.0 5.01324503311 40% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1357.0 1373.03311258 99% => OK
No of words: 276.0 270.72406181 102% => OK
Chars per words: 4.91666666667 5.08290768461 97% => OK
Fourth root words length: 4.07593519647 4.04702891845 101% => OK
Word Length SD: 2.44546429767 2.5805825403 95% => OK
Unique words: 132.0 145.348785872 91% => More unique words wanted.
Unique words percentage: 0.478260869565 0.540411800872 88% => More unique words wanted or less content wanted.
syllable_count: 422.1 419.366225166 101% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 6.0 3.25607064018 184% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 4.0 2.5761589404 155% => OK
Performance on sentences:
How many sentences: 13.0 13.0662251656 99% => OK
Sentence length: 21.0 21.2450331126 99% => OK
Sentence length SD: 46.8489957456 49.2860985944 95% => OK
Chars per sentence: 104.384615385 110.228320801 95% => OK
Words per sentence: 21.2307692308 21.698381199 98% => OK
Discourse Markers: 8.84615384615 7.06452816374 125% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 4.0 4.19205298013 95% => OK
Sentences with positive sentiment : 4.0 4.33554083885 92% => OK
Sentences with negative sentiment : 6.0 4.45695364238 135% => OK
Sentences with neutral sentiment: 3.0 4.27373068433 70% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.104183928001 0.272083759551 38% => The similarity between the topic and the content is low.
Sentence topic coherence: 0.047905295337 0.0996497079465 48% => OK
Sentence topic coherence SD: 0.0251377755259 0.0662205650399 38% => Sentences are similar to each other.
Paragraph topic coherence: 0.0703547016098 0.162205337803 43% => OK
Paragraph topic coherence SD: 0.0302345429179 0.0443174109184 68% => OK
Essay readability:
automated_readability_index: 12.4 13.3589403974 93% => 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: 11.26 12.2367328918 92% => OK
dale_chall_readability_score: 8.23 8.42419426049 98% => OK
difficult_words: 62.0 63.6247240618 97% => OK
linsear_write_formula: 8.0 10.7273730684 75% => OK
gunning_fog: 10.4 10.498013245 99% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
---------------------
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.