The potential energy of this ball is proportional to its height.

The place of articulation is a very important concept in phonetics.

His usual location is the seat at the very back of the library.

My friend came from the Republic of South Sudan.

He is an American.

The American bison is a large mammal native to North America.

The North American beaver is a large rodent native to North America.

The wood duck is a very beautiful bird.

The American bison is a large mammal native to North America.

An American alligator can move very quietly underwater.