Writing prompt: Will E-book Be Necessary in the Future?

Student essay:
As we all know, with the development of science and technology ,E-books are more and more popular . At the same time,the production of traditional books are decreasing step by step.
Everying coin has two sides .E-books also have advantages and disandantages .First ,with the wide use of computes and celephones, we can see that people use them to read any books they want to read everywhere . so ,we can find it more convenient and frivolus .What's more ! It is more easy to carry out outside .Second, I think E-books are cheaper than traditional books. For example ,we can download books from the Internet for free or we can read them directly online besides , if you are tired to read the book now ,you can preserve it and you can read this place the next time .The last one but not the least one,E-books are more envirmental protection .we don't need to cut trees to make books which made of paper. It is known to all that disasters are hanppened frequently and the most important reason for the phenomenon is the decreasing of trees .so ,if we read E-books ,we can protect trees being destroyde .
E-books also have dis adevantages .Reading E-books for a long time can harm our eyes . And we can't make signs on the contents which we think it is important and useful . So that the books will not have more influence on me .
As far as I am concerned ,we can read some not so important books by computers and celephone .And we can look into the distance after the long time reading .In my mind it's necessary of the E-books existence .

Corrected essay:
As we all know, with the development of science and technology, E-books are more and more popular. At the same time, the production of traditional books is decreasing step by step.
Every coin has two sides. E-books also have advantages and disadvantages. First, with the wide use of computers and cellphones, we can see that people use them to read any books they want to read everywhere. So, we can find it more convenient and frivolous. What's more, it is easier to carry outside. Second, I think E-books are cheaper than traditional books. For example, we can download books from the Internet for free or we can read them directly online. Besides, if you are tired of reading the book now, you can preserve it and you can read from this place the next time. Last but not least, E-books are more environmentally friendly. We don't need to cut trees to make books which are made of paper. It is known to all that disasters happen frequently, and the most important reason for the phenomenon is the decrease in trees. So, if we read E-books, we can protect trees from being destroyed.
E-books also have disadvantages. Reading E-books for a long time can harm our eyes. And we can't make signs on the contents which we think are important and useful, so that the books will not have more influence on me.
As far as I am concerned, we can read some not so important books on computers and cellphones. And we can look into the distance after a long time reading. In my mind, it's necessary for E-books to exist.