He is an expert in paleontology and is researching dinosaurs.

He is an expert in nuclear physics.

In chemistry class, I learned about basic oxides.

In chemistry class, I learned about acidic oxides.

Bioweapons are a major threat to humanity.

In this experiment, we will observe the reaction of organic compounds.

In this experiment, we will use various inorganic compounds.

I love stir-fried pork.

That person is my friend.

I saw many animals at the zoo.