1) The world's first stock exchange was established in Amsterdam in 1602.

2) The Sydney Opera House, situated in Sydney, Australia, is an iconic architectural masterpiece and a UNESCO World Heritage site. Its unique design, resembling sailboats or shells, has made it one of the most recognized and photographed landmarks in the world.

3) 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.

4) The largest known dinosaur, Argentinosaurus, weighed around 70-100 tons and measured up to 100 feet in length.