>> explain the four reasons social change movements erupted in the united states in the 1960's.

1.) the british invasion & the birth of rock n roll

2.) the presence and power of leaders like JFK & MLK Jr

3.) the post WWII generation was coming of age (late teens early 20s) and was rebeling against their 1950s upbringing

4.) emerging national mass media coverage of hate crimes through radio, newspaper, and television

Explanation:

worldwide, 780 million people do not have access to an improved water source. an estimated 2.5 billion people lack access to improved sanitation (more than 35% of the world's population)