1) Democracy is a system of government in which power is vested in the people, who exercise it through elected representatives. It allows for political participation, freedom of speech, and protection of individual rights and liberties.

2) The Federal Reserve System, often referred to as the Fed, is the central banking system of the United States.

3) The national animal of Australia is the kangaroo.

4) The Great Rift Valley is a geological feature that stretches over 6,000 kilometers (3,700 miles) from Lebanon to Mozambique. It is known for its diverse landscapes, including deep lakes, volcanic mountains, and fertile valleys, and is considered a significant site for the study of Earth's tectonic activity.