The Okinawa rail, a species endemic to Okinawa Prefecture, is designated as an endangered species.

He failed in business and had a bitter experience.

I use bitter almond oil dissolved in water for skin care.

The monkey-eating eagle, also known as the Philippine eagle, is known for eating monkeys, as its name suggests.

The Monkey-eating Eagle, also known as the Philippine Eagle, is the national bird of the Philippines and is listed as an endangered species.

A coolie was a type of worker in the past.

Alkali metals are very reactive chemically.

Her ring was adorned with a beautiful topaz.

The calculation of the arccotangent is a part of trigonometry.

A quark is a type of elementary particle, and it is a component of protons and neutrons.