你的同桌对你文具盒的文具用品充满了好奇，但不知用英语怎么表达

What's this?
This's a pen.
How to spell?
P-e-n.
How to use?
Like this.
How about that？
That's a rubber.
How to spell?
R-u-b-b-e-r.
Is that pencil?
Yes,it is.
Your pencil-case is beautiful.
Thank you.

What's this in English? It's a pen/ pencil/ sharpener/ eraser/ ruler....
What does pen/ pencil use for? We can write with a pen or a pencil.
What does eraser use for? When we write something wrong, we can use an eraser to move it and rewrite again.
What does ruler use for? When we have to draw straight lines, rule helps a lot.
...
Thanks a lot.
You're welcome.