Car manufacturers and governments have been eagerly seeking a replacement for the automobile's main source of power, the internal-combustion engine. By far the most promising alternative source of energy for cars is the hydrogen-based fuel-cell engine, which uses hydrogen to create electricity that, in turn, powers the car. Fuel-cell engines have several advantages over internal-combustion engines and will probably soon replace them.
One of the main problems with the internal-combustion engine is that it relies on petroleum, either in the form of gasoline or diesel fuel. Petroleum is a finite resource; someday, we will run out of oil. The hydrogen needed for fuel-cell engines cannot easily be depleted. Hydrogen can be derived from various plentiful sources, including natural gas and even water. The fact that fuel-cell engines utilize easily available, renewable resources makes them particularly attractive.
Second, hydrogen-based fuel cells are attractive because they will solve many of the world's pollution problems. An unavoidable by-product of burning oil is carbon dioxide, and carbon dioxide harms the environment. On the other hand, the only byproduct of fuel-cell engines is water.
Third, fuel-cell engines will soon be economically competitive because people will spend less money to operate a fuel-cell engine than they will to operate an internal-combustion engine. This is true for one simple reason: a fuel-cell automobile is nearly twice as efficient in using its fuel as an automobile powered by an internal-combustion engine is. In other words, the fuel-cell powered car requires only half the fuel energy that the internal-combustion powered car does to go the same distance.
The reading states that we will soon replace internal-combustion engines with fuel-cell engines using hydrogen as a source to power cars, due to the reasons mentioned that fuel-cells are more beneficial. However, the professor concurs the author's argument that combustion engines are counterproductive but she confirms that hydrogen is not the solution.
First of all, the professor in the lecture posits that hydrogen is not available readily. Although, there are many sources encompassing hydrogen such as water, but purifying hydrogen is very difficult because for reaching hydrogen, we need to...
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Attribute Value Ideal
Score: 26 in 30
Category: Very Good Excellent
No. of Grammatical Errors: 0 2
No. of Spelling Errors: 0 2
No. of Sentences: 12 12
No. of Words: 276 250
No. of Characters: 1504 1200
No. of Different Words: 145 150
Fourth Root of Number of Words: 4.076 4.2
Average Word Length: 5.449 4.6
Word Length SD: 2.949 2.4
No. of Words greater than 5 chars: 120 80
No. of Words greater than 6 chars: 104 60
No. of Words greater than 7 chars: 76 40
No. of Words greater than 8 chars: 47 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 23 21.0
Sentence Length SD: 11.18 7.5
Use of Discourse Markers (%): 0.75 0.12
Sentence-Text Coherence: 0.423 0.35
Sentence-Para Coherence: 0.618 0.50
Sentence-Sentence Coherence: 0.178 0.07
Number of Paragraphs: 4 4