【电】 set class
gather; troop together; aggregate; assemble; concourse; convene; muster
rendezvous; congregation; concentration
【计】 disjoint set
【医】 aggregate; aggregation; agmen; agmina; convergence
【经】 assembly
rank; scale; grade; notch; rate; social estate; step
【化】 scale
【医】 level
【经】 class; classification; grade; rank