1) The assassination of Archduke Franz Ferdinand of Austria in 1914 triggered the start of World War I.

2) The global response to climate change includes the Paris Agreement, an international treaty aiming to limit global warming and strengthen countries' efforts to address climate change through mitigation and adaptation strategies.

3) The fastest land animal is the cheetah, capable of reaching speeds up to 70 miles per hour (113 kilometers per hour) in short bursts.

4) The first photograph of a black hole was captured in 2019 using a network of telescopes around the world.