n.集中；专心；浓度
The tennis players need total concentration during play. 网球运动员在比赛中需要全神贯注。
Concentration is essential if you want to do a good job. 如果你想把事情做好,专心是必要的。
His area of concentration is economics. 他专心研究经济学。
Check oxygen concentration by a refractometer. 用折射仪测量一下氧气的浓度。
Titanium is useful at low concentration only. 钛只在低浓度时起作用。
浓聚物
n.分散
