1) The concept of political stability refers to the ability of a government or political system to maintain continuity, order, and effective governance over a prolonged period, promoting social cohesion and economic development.

2) The most-watched TV series finale in the United States was "MAS*H," with an estimated 105 million viewers.

3) The phenomenon known as "black holes" occurs when matter is crushed into an infinitely small space, creating a gravitational pull so strong that nothing can escape.

4) The Southern Ocean surrounds Antarctica and is the coldest and least-visited ocean.