Kaitlyn Boettner!

A screw is an Inclined Plane wrapped around

the center core. Screws can change twisting motion for

up and down. Screws can push things together.

Screws were invented in ancient times. They were invented in Egypt. It was very hard to make. They made it by hand. It took a wile.

There is sharp screws Old screws. A different kind of screws is a Thread.