1) The legislative branch in many democracies is responsible for making laws, representing the interests of the people, and providing checks and balances on the executive branch.

2) 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.

3) The blue whale is the largest animal to have ever existed, with an average length of about 82 feet (25 meters).

4) The Danube River, flowing through ten countries in Central and Eastern Europe, is the second-longest river in Europe. It has played a significant role in the cultural and economic development of the regions it traverses and is a popular waterway for river cruises.