This compound mainly consists of octadecanoic acid.

His nature is very kind, and he is liked by everyone.

I like to study new languages.

Octadecane is one of the important hydrocarbons in organic chemistry.

I attended a math class today.

I will teach mathematics to new students tomorrow.

The sourness of this lemon is very strong.

He is majoring in chemistry at university.

In chemistry class, I learned about the properties of octadecanoic acid.

He is an expert in chemistry.