Rectangular Prism
Depends on what kind of eraser you are talking about, and what kind of teeth. They do sell stain erasers for dentures that should work. If you are just talking about the eraser on the end of a pencil, then no.
same eraser both on white boards and chalk boards?
Yes, the noun 'eraser' is a common noun; a general word for an object, a device, or a substance; a word for any eraser of any kind.
a rectangle, or a rectangular prism
STAEDTLER mars plastic
If you rub hard enough, a regular eraser found on top of a pencil, or other kind of regular eraser will rub out colored pencil. If the colored pencil was drawn roughly on the paper, and pressed hard enough into the paper, the colored pencil cannot be rubbed out. You can try an ink eraser (the kind of eraser found on erasing ink pens), but it may or may not work.
Internet eraser software is considered to be of the privacy category of computer software, as internet eraser software when used erases any internet history and online activity logs from a computer system.
duke snookies
If you've already tried washing it with soap and water, then try an eraser. Regular kind or the Mister Clean Eraser thingy.
im board
The board that you get depends with the products that you will be promoting.
If your just beginning, neither. Get a cheaper board that you can learn on, and figure out whether or not you really want to get into longboarding. Once you know that, research the aspects of different boards and what kind of riding you'll be doing and use that as a guide to buy a board.