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

I learned about the properties of chloral in chemistry class.

I like to study new languages.

I attended a math class today.

I will teach mathematics to new students tomorrow.

He is majoring in chemistry at university.

He is an expert in chemistry.

The use of mobile phones is prohibited during class.

There is a class observation at my son's school tomorrow.

This reaction occurs through a chemical process.