To "scour" means to clear an area or region of enemies or outlaws (i.e. "scour the area for our enemies and make sure they are eliminated). To "search" is to examine an area or region with the intention of locating something or someone. "Scouring" involves locating and eliminating an enemy; to search is to simply locate someone or something.
Okay i will you are right
I've heard the Ganges River is very polluted and filthy. Indians throw trash in there. It was known for its beauty. People bathed in its waters believing it was holy. That is one reason it is so dirty. It would take a very long time considering the fact that the Ganges River is one of the longest in India, with the Indus River at first place.
The Answer SHOULD be the first one, The Soviet Union Imprisoning its critics.
That would be "Containing" the critics most likely against their will.