1) The President of the United States serves as the head of state and the head of government, responsible for leading the executive branch and representing the nation domestically and internationally.

2) A group of flamingos is called a "flamboyance."

3) The world's oldest living plant is believed to be a clonal shrub called "Old Tjikko" in Sweden, estimated to be over 9,500 years old.

4) The Mongol Empire, under the leadership of Genghis Khan, became the largest contiguous empire in history, spanning from Asia to Europe.