TOEFL integrated writing: fuel-cell engines

The article states that, fuel-cell engines have several advantages over internal-combustion engines. However the professor explains that it is not true and using fuel-cell engines will not be a solution for a variety of problems such as pollution and expenses, she refutes each of the author's reasons.

First the reading states that, the main problem of internal-combustion engines is relying on petroleum and gasoline. The professor rejects this point by stating that the hydrogen, which is uses in fuel-cell engines, is not easily available. She mentions that, although water includes hydrogen, it is not usable. She informs that pure hydrogen is liquid and it exists in mines 253 degree of Celsius. So that, producing and storing of that is very difficult.

Second, the article claims that hydrogen-based fuel cells will reduce world’s pollution. However, the professor contends that producing hydrogen is not easy and this action will add much more pollution to air. For instance she says, burning coil to extract hydrogen from water is very filthy step and will add pollution to air.

Third, reading avers that using fuel-cell engines is commodious and people will have tendency to that. The lecture opposes this point by saying that the steps of producing hydrogen are expensive. She says that for production of hydrogen they need to platinum which is the main item in special chemical reactions of production. And unfortunately it is expensive and there is no substitute for that.

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Average: 8 (2 votes)
Essay Categories

Sentence: The professor rejects this point by stating that the hydrogen, which is uses in fuel-cell engines, is not easily available.
Description: The token is is not usually followed by a noun, plural, common
Suggestion: Refer to is and uses

Attribute Value Ideal
Score: 24 in 30
Category: Good Excellent
No. of Grammatical Errors: 1 2
No. of Spelling Errors: 0 2
No. of Sentences: 14 10
No. of Words: 239 250
No. of Characters: 1221 1200
No. of Different Words: 124 150
Fourth Root of Number of Words: 3.932 4.3
Average Word Length: 5.109 4.6
Word Length SD: 2.823 2.4
No. of Words greater than 5 chars: 93 60
No. of Words greater than 6 chars: 79 50
No. of Words greater than 7 chars: 50 40
No. of Words greater than 8 chars: 29 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 17.071 21.0
Sentence Length SD: 6.262 7.5
Use of Discourse Markers (%): 0.5 0.12
Sentence-Text Coherence: 0.354 0.35
Sentence-Para Coherence: 0.559 0.50
Sentence-Sentence Coherence: 0.149 0.07
Number of Paragraphs: 4 4