1) 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.

2) The Appalachian Mountains, running along the eastern coast of the United States, are one of the oldest mountain ranges in the world.

3) The first modern Olympic marathon race was held at the 1896 Olympics in Athens and has since become one of the most iconic and challenging events in athletics.

4) The Dead Sea, bordered by Jordan to the east and Israel and Palestine to the west, is a hypersaline lake known for its high salt concentration. It is the lowest point on Earth's land surface and provides unique buoyancy, attracting visitors who enjoy floating in its waters.