Request to correct grammar mistakes, thank you.

Enthusiasm and attention are used strangely and not smoothly.

One is correct and the other is a noun. It is best to use the same part of speech, otherwise foreigners will feel connected, but they can still communicate.

Therefore, I am writing this letter to show my suggestions on the books I want to buy as follows.

This sentence is really. . . . It's not good, but it should be okay.

But you may have some misunderstandings. Some of my suggestions are my suggestions.

Not some of my suggestions.

I guess you need to buy some books recommended by yourself.

The word display is usually used for things that can be seen on monitors or signboards.

Then, is this a third-person verb or a plural noun? Usually used as a noun, it can be written directly as follows.

Only means only, but you can't use and because these are two payment methods.

It can be changed to only cash or card, which is the second choice: 1.

Last but not least, wrap them in a strong shell to prevent books from being damaged.

I don't know what you're trying to say, but I guess what you're trying to say is to use boxes to protect books from being damaged.

Finally, please pack it in a strong box with plastic shell to avoid any invisible damage.