TOEFL Integrated Writing Task - Best answer

I said I would post the best essay I've received on the integrated writing task. This is the one I've picked and it's written by U.  My comments are included.

Writing essay homework 2
Topic: Tidal power

 According to the lecture, the professor gives some opinions about a tidal power that differ from the reading passage. Most details in the passage focus on advantages of the tidal power on energy generation while the lecture states the opposite. The professor mentions some disadvantages of this kind of power that cast doubts on the reading passage.
 First, the passage shows that the tidal power can provide a renewable energy generation that could be a useful energy supplement in the future. By contrast, the professors says that this amount of energy is small and can supply only a particular region, not for a large area. Therefore, it will not be practical as an important alternative energy source.
 Another point that the professor casts doubts on the tidal power is its environmental drawbacks. Although the passage support the tidal power because of its non-polluting quality, she states that a dam or estuary change the water flow. Fishes cannot migrate across the dam and many animals, including birds, lose their habitats and foods.
 Furthermore, the lecture states that human also receive the bad points of the tidal power’s energy generation not only in the environment aspects, but also the economic problem. This ______because their fishing work cannot navigate across the estuary.
 In conclusion, the professor argues some reasons that show many disadvantages of the tidal power. These reasons cast doubts on the reading passage whether this power really give us a benefit or not. 

Very good essay again U.
You have argued your case very well and would get a top score for this essay. I have underlined where you are making some mistakes – articles, 3rd person verbs and countable/uncountable nouns.
I’ll send you some practice sheets for your grammar.