Dense urban centers, wherer they worked to strengthen immigrant communities
Diffusion is the movement of particles/molecules from a high concentrated area to a low concentrated area until they are evenly spread.
'Concentrated' means to focus on something intensely, or to be denser or more potent than usual.
There were no leaders they just fought. I bet they thought of having leaders but they didn't think that it would work having people telling other people what to do. It just didn't work out so they didn't have leaders.
Leaders work well either way.
Initially his job was to help mankind. But he introduce temptation.
Use limeaway (the concentrated type) or clr (concentrated). Both work pretty well. They are very strong and can be bought at home depot or lowes.
Leaders can show new employees how to do the least possible amount of work.
Initially, she worked in Calcutta, India, but her work has now spread world wide.
govener
Bureaucracy.
I would suppose the word "initially" might work.
There are multiple official meanings for the word concentrated. The most common used and best known meaning is "focused". If one is concentrated, one is focused on work at hand.