Definition: The atmosphere is the air that surrounds the Earth. You can't see the atmosphere, but you can feel it when the wind blows.

Sentence: Up and over! Upside down! Up above the atmosphere!

Definition: A ukulele is a musical instrument that is like a small guitar with four strings.

Sentence: I played the ukulele while my friend played the drums.

Definition: A uniform is the clothes that everyone wears in some schools or in some groups so that they are all dressed the same.

Sentence: My favorite soccer player wears a red uniform.