How someone brush their teeth in space and why?

First, the astronaut attaches their toothpaste tube to a nearby wall. With the toothbrush in one hand and the drink pouch in the other, they squeeze a small bead of water from the pouch while simultaneously gliding their toothbrush over it. The toothbrush will instantly suck up the water.

Explanation:

They do it for the same reason we do

answer ( groundwater);