Short "oo" sound:
* Book
* Look
* Cook
* Took
* Foot
* Good
* Wood
* Wool
* Put
* Pull
* Push
* Full
* Bull
Longer "oo" sound (more like "oooh"):
* Soon
* Moon
* Spoon
* Rooster
* Boom
* Room
* Doom
* Bloom
These are just a few examples. There are many other words that share the same vowel sound!