名詞 concentration:

1. (chemistry) the strength of a solution; number of molecules of a substance in a given volume (expressed as moles/cubic meter)
2. the spatial property of being crowded together
   同義詞：density, denseness, tightness, compactness
3. 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
4. increase in density
5. complete attention; intense mental effort
   同義詞：engrossment, absorption, immersion
6. bringing together military forces
7. great and constant diligence and attention
   同義詞：assiduity, assiduousness

1. The tennis players need total concentration during play.
   網(wǎng)球運動員在比賽中需要全神貫注。
2. The drug affects one's power(s) of concentration.
   這種藥影響人精神不能集中。
3. The inward flow of a fluid through a permeable membrane toward a fluid of greater concentration.
   內滲透一種液體透過可滲透膜流向另一種濃度比它高的液體的內部流動
4. A state of mental concentration.
   專心致志，全神貫注全神貫注的狀態(tài)
5. I found it hard to keep my concentration with such a noise going on.
   吵鬧聲不絕于耳，我很難保持精神集中。
6. Stress and tiredness often result in a lack of concentration.
   緊張和疲勞常使人精神不集中。

con.cen.tra.tion

n.（名詞）

The act or process of concentrating, especially the fixing of close, undivided attention.
專心：全神貫注的動作或過程，尤指專注的、不分散的注意力的集中
The condition of being concentrated.
全神貫注的狀態(tài)
Something that has been concentrated.
經過濃縮的物品
Chemistry The amount of a specified substance in a unit amount of another substance.
【化學】 濃度：在某一單位物質中另一特定物質的含量