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.
Question：Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific points made in the reading passage.
The reading maintains that pterosaurs were not able to fly by their wings or glide. However, the professor in the lecture disagrees with the reasons mentioned in the reading and gives her own views.
Firstly, the reading cotends that it is likely that pterosaurs were cold-blooded like modern reptiles and they could not produce enough energy to fly. But the professor says that hair and furs are typical among pterosaurs which can help maintain body temperature. Then they could supply energy to fly by their own.
Secondly, the reading believes that due to the fact that pterosaurs were heavy and they could not fastly flap their wings in order to keep flying. However, the professor thinks that although pterosarus were large, they had unusual body weight. Although they looked large, their bones were hollow, making their total weight low enough to fly.
Finally, what the reading says is that pterosaurs had difficulty taking off the ground for their leg mucles were not strong enough to launch themselves and were also small and weak. On the contrary, the professor argues that the way pterosaurs launched is different from birds. Birds use two legs to take off, while pterosaurs utilized their four legs. And they would push off the ground to fly.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2019-12-06 | marii.r67 | 80 | view |
| 2019-11-13 | shirley5001 | 80 | view |
| 2019-11-13 | shirley5001 | 80 | view |
| 2019-11-03 | Seema Modak | 78 | view |
| 2019-11-03 | Seema Modak | 78 | view |
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Transition Words or Phrases used:
also, but, finally, first, firstly, however, if, look, second, secondly, so, then, while, on the contrary
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 11.0 10.4613686534 105% => OK
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 9.0 7.30242825607 123% => OK
Relative clauses : 10.0 12.0772626932 83% => OK
Pronoun: 25.0 22.412803532 112% => OK
Preposition: 22.0 30.3222958057 73% => OK
Nominalization: 0.0 5.01324503311 0% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1054.0 1373.03311258 77% => OK
No of words: 210.0 270.72406181 78% => More content wanted.
Chars per words: 5.01904761905 5.08290768461 99% => OK
Fourth root words length: 3.80675409584 4.04702891845 94% => OK
Word Length SD: 2.28420585147 2.5805825403 89% => OK
Unique words: 118.0 145.348785872 81% => More unique words wanted.
Unique words percentage: 0.561904761905 0.540411800872 104% => OK
syllable_count: 299.7 419.366225166 71% => OK
avg_syllables_per_word: 1.4 1.55342163355 90% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 6.0 8.23620309051 73% => OK
Subordination: 2.0 1.25165562914 160% => OK
Conjunction: 2.0 1.51434878587 132% => 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: 17.0 21.2450331126 80% => The Avg. Sentence Length is relatively short.
Sentence length SD: 39.0113943469 49.2860985944 79% => OK
Chars per sentence: 87.8333333333 110.228320801 80% => OK
Words per sentence: 17.5 21.698381199 81% => OK
Discourse Markers: 8.75 7.06452816374 124% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 0.0 4.19205298013 0% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 4.0 4.45695364238 90% => 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: 0.220486962512 0.272083759551 81% => OK
Sentence topic coherence: 0.0894056404994 0.0996497079465 90% => OK
Sentence topic coherence SD: 0.0630943559287 0.0662205650399 95% => OK
Paragraph topic coherence: 0.146386330134 0.162205337803 90% => OK
Paragraph topic coherence SD: 0.0137233982074 0.0443174109184 31% => 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: 11.0 13.3589403974 82% => Automated_readability_index is low.
flesch_reading_ease: 71.14 53.8541721854 132% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 7.6 11.0289183223 69% => OK
coleman_liau_index: 11.54 12.2367328918 94% => OK
dale_chall_readability_score: 7.41 8.42419426049 88% => OK
difficult_words: 39.0 63.6247240618 61% => More difficult words wanted.
linsear_write_formula: 7.5 10.7273730684 70% => OK
gunning_fog: 8.8 10.498013245 84% => OK
text_standard: 8.0 11.2008830022 71% => OK
What are above readability scores?
---------------------
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.