This festival is held every year.

I attended a math class today.

I will teach mathematics to new students tomorrow.

We conducted an experiment on electrolysis in chemistry class.

The chemist electrolyzed water to produce hydrogen and oxygen.

He is majoring in chemistry at university.

We conducted a new experiment in science class.

We will conduct a new chemistry experiment tomorrow.

He is an expert in chemistry.

The use of mobile phones is prohibited during class.