Her smile is very natural, and it feels comfortable.

In philosophy, natural law refers to the moral laws of the universe.

The equilibrium length of this spring is 5 centimeters.

He prefers natural foods.

This wood may spontaneously combust if the humidity is high.

His car spontaneously combusted all of a sudden.

Natural rights are rights that humans have from birth.

He claims to be a warrior for freedom of expression, but in reality, he's just someone who uses derogatory words.

Natural language processing is a technology that allows computers to understand and analyze human language.

He is writing a thesis on abiogenesis.