Your prompt response is not on the mark. You are agreeing with both sides to some degree rather than choosing a single opinion to discuss in an expanded form. You cannot discuss both sides in a single opinion essay. The problem lies in the way that you formed your response. You indicated:
To some extent, I agree that students can study well at home with the help of the Internet, I feel that schools still play a vital role in our society and cannot be replaced no matter what.
The presentation is incorrect as I explained above. The reference must only be made to the discussion you will be using in your reasoning paragraphs, along with the basic reasoning for it. For example:I strongly believe that schools cannot be replaced by the internet based on 2 specific reasons. (Indicate reasons 1 and 2 or 2 topics for discussion)
Since your reasoning paragraphs are also problematic, I will have to tell you that only the 2nd reasoning paragraph, the one that defends why schools cannot be replaced, will get a scoring consideration. That is because it is the only paragraph that supports the opinion you provided (schools cannot be replaced).
Therefore, this essay will struggle to get a passing score. There are 2 problem areas, as I indicated above, which will lower the scoring basis for the presentation. Remember, when not asked to compare or discuss both views, you are expected to use only the single point of view defense / discussion. Otherwise, the essay will be deemed under developed / under explained, and receive low marks for it based on overall discussion considerations.