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

2) The concept of federalism involves the division of powers between a central government and regional or local governments, allowing for shared governance and autonomy for different levels of administration.

3) The development of the microprocessor by Intel in 1971 paved the way for the modern computer and led to the exponential growth of computing power.

4) The strongest natural material known to man is spider silk. It is stronger than steel and more flexible than nylon.