Pterosaurs were an ancient group of winged reptiles that lived alongside the dinosaurs. Many pterosaurs were very large, some as large as a giraffe and with a wingspan of over 12 meters. Paleontologists have long wondered whether large pterosaurs were capable of powered flight (flying by flapping their wings) or whether they were able only to glide. Several arguments have been made against powered flight.
Doubters point out that since modern reptiles are cold-blooded, ancient reptiles such as pterosaurs were probably cold-blooded as well. Cold-blooded animals typically have a slow metabolism and are unable to produce a lot of energy. Powered flight is an activity requiring a lot of energy, which is why all modern vertebrates that fly are warm-blooded, not cold-blooded. It seemed unlikely that pterosaurs would have been able to generate the energy needed to fly.
Second, there is a limit to the weight of animals that can be kept airborne by powered flight. Pterosaurs that were as large as a giraffe were probably so heavy that they would not have been able to flap their wings fast enough to stay aloft for any length of time.
Third, all animals with powered flight are able to take off from the ground. For example, birds take off by jumping from their legs or running to gain speed and then jumping. But these methods would not have worked for large pterosaurs. Large pterosaurs would have needed big, powerful muscles in their back legs to launch themselves into the air, and we know from fossilized bones that their back leg muscles were too small and weak to allow the pterosaurs to run fast enough or jump high enough to launch themselves into the air.
The reading and listening passages discuss whether pterosaurs could fly or just glide. The author proposes three theories to oppose pterosaurs can fly. However, the speaker holds these arguments questionable.
First of all, the article claims that pterosaurs were probably cold-blooded so that they would have not been able to generate the energy to fly. Nevertheless, the lecture points out that many pieces of evidence show that pterosaurs might not be cool-blooded. For example, they had hair and fur, which indicate that they probably were warm-blooded dinosaurs. Therefore, if they really are warm-blooded creatures, they might have enough energy to supply their flight.
Second, the writer says pterosaurs were too large and weight to able to flap their wings fast enough to stay aloft. On the other hand, the lecturer argues that they are actually more light than we thought. According to the structure of bones of pterosaurs, bones are the hollow structure, which let pterosaurs with low weight. And because of such structure, it could make pterosaurs fly into skies.
Furthermore, the author states that pterosaurs' back leg is too small and weak to allow them to run fast or jump high to launch into the air. However, the speaker contends that pterosaurs are not likely many birds using only two legs to push themselves into skies, instead, they are using four legs to launch. Thus, they have not any trouble to run or jump to make them have the power to leave the ground.
To sum up, all the arguments mentioned in the reading passage are plausible according to the speaker.
Transition Words or Phrases used:
actually, first, furthermore, however, if, nevertheless, really, second, so, therefore, thus, for example, first of all, to sum up, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 12.0 10.4613686534 115% => OK
Auxiliary verbs: 6.0 5.04856512141 119% => OK
Conjunction : 8.0 7.30242825607 110% => OK
Relative clauses : 10.0 12.0772626932 83% => OK
Pronoun: 24.0 22.412803532 107% => OK
Preposition: 31.0 30.3222958057 102% => OK
Nominalization: 1.0 5.01324503311 20% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1334.0 1373.03311258 97% => OK
No of words: 263.0 270.72406181 97% => OK
Chars per words: 5.07224334601 5.08290768461 100% => OK
Fourth root words length: 4.02706775958 4.04702891845 100% => OK
Word Length SD: 2.57434386005 2.5805825403 100% => OK
Unique words: 153.0 145.348785872 105% => OK
Unique words percentage: 0.58174904943 0.540411800872 108% => OK
syllable_count: 388.8 419.366225166 93% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 5.0 3.25607064018 154% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 3.0 2.5761589404 116% => OK
Performance on sentences:
How many sentences: 15.0 13.0662251656 115% => OK
Sentence length: 17.0 21.2450331126 80% => The Avg. Sentence Length is relatively short.
Sentence length SD: 29.4364852974 49.2860985944 60% => The essay contains lots of sentences with the similar length. More sentence varieties wanted.
Chars per sentence: 88.9333333333 110.228320801 81% => OK
Words per sentence: 17.5333333333 21.698381199 81% => OK
Discourse Markers: 9.93333333333 7.06452816374 141% => OK
Paragraphs: 5.0 4.09492273731 122% => OK
Language errors: 0.0 4.19205298013 0% => OK
Sentences with positive sentiment : 4.0 4.33554083885 92% => OK
Sentences with negative sentiment : 4.0 4.45695364238 90% => OK
Sentences with neutral sentiment: 7.0 4.27373068433 164% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.222345536724 0.272083759551 82% => OK
Sentence topic coherence: 0.0707607584375 0.0996497079465 71% => OK
Sentence topic coherence SD: 0.0547066126202 0.0662205650399 83% => OK
Paragraph topic coherence: 0.105516860406 0.162205337803 65% => OK
Paragraph topic coherence SD: 0.0627258536261 0.0443174109184 142% => OK
Essay readability:
automated_readability_index: 11.2 13.3589403974 84% => Automated_readability_index is low.
flesch_reading_ease: 62.68 53.8541721854 116% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 8.7 11.0289183223 79% => OK
coleman_liau_index: 11.83 12.2367328918 97% => OK
dale_chall_readability_score: 7.48 8.42419426049 89% => OK
difficult_words: 50.0 63.6247240618 79% => More difficult words wanted.
linsear_write_formula: 6.5 10.7273730684 61% => OK
gunning_fog: 8.8 10.498013245 84% => OK
text_standard: 9.0 11.2008830022 80% => OK
What are above readability scores?
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Rates: 85.0 out of 100
Scores by essay e-grader: 25.5 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.