However, most people believe that the internet gives us opportunities to open our minds. But it is extremely diffucult to only try to expand outlook.Another argument for surfing the web is that people do not want to carry heavy books in their bags. Actually, the internet is not one of the important things for our development because as I say there are too many flimsy things that can pervert us.
In conclusion, I would like to say that we should use only concrete sources for our personal development and be able to use them without basing on the internet.
The first paragraph does not show your attitude about the issue as a whole. That is also a part that you may improve.
Please remember highlight a single point at the first sentence in a paragraph and sprawling the single point in the following sentences with a couple of evidence or instances. That will make your statement sound, clear and understandable. Do not stress more than 2 points in a paragraph, which will terribly confuse the reader.
I'm going to comment only on your posting as an essay, without trying to correct the English.
Your opening paragraph is good. It introduces the topic. It teases the reader by hinting at your answer--in the form of a question, which makes us want to read more to find out what your answer is.
Your second paragraph is good. It has a good topic sentence. You say what the paragraph is going to be about (drawbacks) and you then give three specific examples.
Your third paragraph is a miscellaneous grab-bag. It isn't clearly organized and doesn't make any clear single point. You make two different points (doesn't help us open our minds; something about not carrying heavy books, but I can't even tell if you agree or disagree with this). Since it is almost a tradition for an essay like this to have five paragraphs--an introduction, a conclusion, and three main points in between--you might want to break this paragraph into two.
Overall, your essay is weak in terms of supporting your opinions with verifiable facts. For example, you say "However, most people believe that the internet gives us opportunities to open our minds." Do most people believe this? Who, exactly, believes this? (And, by the way, do you mean "open our minds," which means enable us to tolerate unfamiliar new ideas, or something else?) It would be a much stronger sentence if you said "So-and-so, writing in 1998, said 'the Internet will make us open-minded.'"
I don't understand "flimsy things that can pervert us." By "flimsy" I think you mean "frivolous." "Perversion" usually means moral corruption. Perhaps you mean "distract." Thus, "The Internet offers too many frivolous distractions." Look up "frivolous" and "distract" in the dictionary to see whether I'm right. Here, a problem is that you haven't supported this statement either. You haven't given us examples of what kinds of flimsy or frivolous material you are referring to, or said how it perverts or distracts us.
