Social networking is based on the six degrees of concept which posits that you can connect with anyone through a chain of no more than six introductions or personal links.

The correct answer in the missing blank is known as "separation".

The six degrees of separation is known as a theory in social networking wherein it states that a person can be connected anyone in the world, no matter how far, through a process of acquaintances, which possesses not more than five mediums.

To solve their problems, mesopotamians used irrigation, a way of supplying water to an area of land. to irrigate their land, they dug out large storafe basins to hold water supplies these ditches brought water to the feilds. to protect their feilds from flooding, farmers built up the banks of the tigris and euphrates.hope ths !