An antiproton is a particle with the same mass as a proton but with opposite charge.

Yoko is my best friend.

A proton is one of the fundamental components of matter.

An antiparticle is a particle that pairs with a matter particle.

Electrons have a negative electric charge.

How much is the mass of this object?

He was running while holding a bag.

He always carries an umbrella around.

He was holding my hand tightly.

We are in the same class.