Many internal-combustion engines are used in cars and motorcycles.

The internal energies of the system are constantly changing.

Internal migrations have increased in recent years.

The iron gums were scattered across the forest floor.

The iron harvests were plentiful this year.

Iron ores are mined and processed to extract iron.

The iron grays galloped across the field.

The iron eagles soared through the sky.

Iron-sulphur proteins are essential for various biological processes.

The iron men stood tall and proud, ready to defend their city.