•The noise outside made concentration difficult.外面吵得我难以集中注意力。

•There was a look of intense concentration on her face.她脸上带着全神贯注的表情。

•I find that yoga improves my powers of concentration.我发现练瑜伽提高了我的注意力。

•I found it hard to follow what the teacher was saying, and eventually I lost concentration.我发现自己难以理解老师在讲甚么，最后就出神了。

•The government's concentration on tax reduction has won them a lot of support.政府集中推行减税政策，从而赢得了广泛的支持。

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•There is a heavy concentration of troops in the area.该地区有重兵驻扎。

•a concentration of one part per million百万分之一的浓度

•High concentrations of toxic elements were found in the polluted areas.在受污染地区发现了高浓度的有毒元素。