Which evidence would be best to add after sentence 7 to support the argument that the paper is still needed?

The best support that line 7 can have for arguing the need for paper is that the only technologies available to replace them that doesn't tire the eye are incredibly expensive.

Explanation:

There are two reasons for this argument. the first one is that blue light is very damaging for the human eye. It creates a syndrome called "tired eye" it means that the eye gets tired and can't watch properly. So with time internal eye pressure increases and can cause glaucoma. Now, there is only one type of technology available for replacing paper without affecting the human eye with blue light. It is called electronic ink. It works by printing real-time images on the screen with electronic ink. Something similar to LCD. However, this technology is really expensive and has not been used to the widescreen market. One single electronic ink monitor of 13 inches without HD capabilities, working at 30 or less fps costs one thousand dollars as a minimum. therefore, the paper is still needed as books' average cost is ten to twenty dollars.

it is the nurture that decides the behavior of a child.

explanation:

naturally, children are pure. it is an environment and the type of attention a child gets that determines their behavior.