Writing Feedback / TOEFL: Some people believe that the Earth is being harmed (damaged) by human [3]

Impressive but some small mistakes can be easily corrected with a litle attention:
Activity --> activities
concurrently with the increase of human consume --> concurrently with the increase of human consumption.
etc.

Writing Feedback / Children spend too much time on computers; IELTS [7]

As far as I know, in term of grammar, Korean is far different from English (although my Korean is quite bad, almost 2 years living in SK brougth me a few words +_+).

Comeback to your essay:
- In general, we should change the struture of yours, you're having a somewhat big head (the opening paragraph) and a small first part of your body. Change it.

- In particular, some simple mistakes on your language usage, grammar... such as:
South Koreans' most families have their home computers -- > Most SK families have their PC/ own computers etc.
Even though, the computer are using in a positive way ---> Eventhough, the computers are now being used in a positive way
When their parents are tried to stop them --> When their parents try to stop them.
and some more passive voice sentences. ^^

I'm also interested in IELTS. coz I will do it this year but I do not have much time to practise +_+

Writing Feedback / Valuing of past is a must; shorten getting knowledge time, avoiding mistakes [3]

wraith
Writing:

Whether learning about (from) the past has any value for those who are living in the present is a provocative topic. Some people hold the idea that this learning is totally worthless because they think that it is better to let the past "rest in peace". However, in my opinion, learning about the past is necessary for the following reasons: it can shorten the time we spend to get knowledge; it helps us to avoid the mistakes in our lives; and it inspire us in our daily lives

Learning about the past can help us to shorten the time for getting knowledge. The human knowledge was accumulated through many generations. Each generation inherits the knowledge from precedents, decants, improves it and bequeaths to their posterities. By getting knowledge from ancestors, a teenager now can have the knowledge equivalent to a savant in the past If people always oppose the knowledge of ancestors, humanity cannot have such improved society, they would still live in cave as our far-far forefathers.

Moreover, learning about the past helps us to avoid the mistakes in our lives. In the past, there are so many man-made catastrophes such as World Wars or atomic bombardments. By examining carefully the causes of these cataclysms, human can preclude both the profound and immediate causes of man-made calamities, therefore humanity can avoid suffering (from) these disasters.

Furthermore, past can also inspire us in our nowadays lives. There are many people in the past who are the mirror(?) of personality. For example, in our (where r u? more specific) country's history, there is a story about a very poor student who has (had)not enough money to buy (a) lamp. To have the light for learning, he must catch some fire-flies and confined them in egg's shell. Eventually, he became a very famous scholar in our country. His mirror has inspired many people in our country and impelled us to work harder and harder in any situation.

From the above discussed reasons , I strongly affirm that treasuring the value of past is a must with us since it can inspire us in daily lives, shorten our getting knowledge time and help us to avoid the mistakes

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A really good essay both agurments and language usage, however, some small mistakes should be improved :)