There is a lot of spirogyra floating in this pond.

In this chemical reaction, hydration plays an important role.

This area is rich in subterranean rivers, which serve as a source of groundwater.

Chromium has the property of changing color depending on its oxidation state.

His new car is black.

His black cat is very cute.

Chimpanzees are very intelligent animals.

Chromium is an important element in the production of steel.

I add a little black pepper to the soup.

I like to add black pepper to the soup.