1) A single bolt of lightning can heat the surrounding air to temperatures five times hotter than the surface of the sun.

2) The political system of the People's Republic of China is based on the Communist Party's leadership, with the General Secretary holding significant authority and influence over the country's policies and governance.

3) In Norse mythology, the Valkyries are divine maidens who serve Odin, the chief god. They are responsible for selecting warriors worthy of entering Valhalla and escorting them to the afterlife. They are often depicted as powerful and beautiful figures, riding winged horses and wielding spears.

4) The development of artificial intelligence (AI) has led to advancements in areas such as machine learning, natural language processing, and computer vision.