名词

1.[C,U]集中

2.不可数名词：专心，专注

3.不可数名词：浓缩；浓度

英语解释

(chemistry) the strength of a solution; number of molecules of a substance in a given volume (expressed as moles/cubic meter)

bringing together military forces

increase in density

the spatial property of being crowded together

complete attention; intense mental effort

great and constant diligence and attention

strengthening the amount of a substance in a unit amount of another substance (as of a solute in a mixture) by removing the other substance