He had a big lump on his head.

I crossed to the island by ferry.

He goes to the dojo every day to learn martial arts.

The 'Naribumi', which started from the Heian period, played an important role in Japanese history.

Hyobu played an important role in the history of Japan.

Her family adopts a matriarchy.

The United Kingdom is a constitutional monarchy.

Oligarchy is a political system where a few powerful people rule the country.

Proportional representation is an important system to ensure the fairness of elections.

My company has introduced a layoff system.