The government of the country is its control system.
Governments make laws and provide services to their citizens.
The land over which a government has control is its territory.
A country's territory(领土) has boundaries(边界线), or borders(边界).
When you leave or enter a country's territory, you usually need a passport.
A country's military provides defense for its territory and its citizens.
A military includes an army, an air force and a navy.
The main purpose of a military is to defend a country from attack.
A country's criminal justice system includes the police, courts and prisons.
Its purpose is to enforce the law and protect people from criminal activities.
A country's social services system provides support to people in need.
It provides basic health care services and helps poor people support their children.