This airplane flies at subsonic speed.

I learned about the reaction of nitrous acid in chemistry class.

Hypochlorous acid is a hypo compound of chlorine.

Amai is my best friend.

It is very interesting to learn about the geography of a subcontinent.

In the past, 'Agun' was used as an abbreviation for 'Alameda County'.

This bird is classified in the suborder of birds.

My friend came from Argentina.

My friend came from Argentina.

My friend is living in Argentina as a resident.