1
general::
Phrase(s): concentrate someone or something at something
to cause people or things to gather at a place; to cause people or things to convene or converge at a place. • You shouldn’t concentrate all the guards at one entrance. • The general concentrated all the big guns at the entrance to the valley., Phrase(s): concentrate at some place
to gather thickly at a place. • The moths concentrated at the window at night, attracted by the light. • All the thirsty children concentrated at the water fountain.
McGrawhill's American Idioms And Phrasal Verbs