He was hiding his amorous preference for boys.

He is a cat lover and plays with his cat every day.

He found a way to profit from a difficult situation like fishing at the bottom of a river.

I use a set square to draw shapes.

In chemistry class, I learned about acid anhydride.

In chemistry class, I learned about acidic oxides.

Lower fatty acids play an important role in the human body.

Essential fatty acids are necessary to be taken from our diet because our body cannot produce them on its own.

Essential amino acids are vital nutrients for the human body.

This fossil is made of carbon.