Hydrocarbons are fundamental components of organic chemistry.

He was involved in the development of the hydrogen bomb.

Hydrogen sulphide is extremely toxic, and particularly at high concentrations, it is lethal to humans.

This compound is stabilized by hydrogenation.

He hydrogenated fatty acids in a chemical experiment.

I maintain my health by doing aerobic exercises every day.

I found an old box in the storeroom.

She felt the pathos of things when she saw the cherry blossoms falling.

What is this object?

Zoo staff must clean up the animals' excrement every day.