Answer:
Some social relations are voluntary and freely chosen (a person chooses to associate with another person or a group). But other social relations are involuntary, i.e. people can be socially related, whether they like that or not, because they are part of a family, a group, an organization, a community, a nation etc.
Explanation:
The Berlin Blockade (1948–49) was the first major crisis of the Cold War. With the victory of the Communist side in the Chinese Civil War and the outbreak of the Korean War (1950–53), the conflict expanded.
The meaning of this quote "A leader is best when people barely know he exists; when his work is done, his aim fulfilled, they will say; we did it ourselves" means if the leader is unknown to many people once he has finished or achieved a remarkable goal other people (such as Laozi) can steal the glory and be remembered for something they didn't do.
<span> They used rivers and streams for fishing, used trees to make shelter and canoes, and they were able to farm the fertile land.
Hope this helps.</span>