Tetrose is a monosaccharide with four carbon atoms.

Carbon is one of the basic elements of life.

He was holding my hand tightly.

He was running while holding a bag.

He always carries an umbrella around.

This problem is simply a matter of not having enough time.

Understanding the structure of atoms is a fundamental part of physics.

Fructose is one of the sugars that is abundant in fruits.

He likes to add sugar to his coffee.

The lens of this camera is easy to attach and remove.