您要查找的是不是：
- His area of concentration is nuclear physics. 他的专门研究范围是原子物理学。
- The drug affects one's power(s) of concentration. 这种药影响人精神不能集中。
- He is an authority in the region of chemistry. 他是化学界的权威。
- It will cost in the region of $500. 它大约得花费五百美元。
- The darkest region of a sunspot. 太阳黑子中的最黑暗的区域
- Stress and tiredness often result in a lack of concentration. 紧张和疲劳常使人精神不集中。
- An exam demands a high level of concentration. 考试时需要全神贯注。
- He travelled in the unexplored regions of the mind. 他遨游于那些未经探索的精神领域。
- The drug may affect your powers of concentration. 这种药可能会影响你的注意力集中。
- The region of the United States west of the Mississippi River. 西部地区美国密西西比河以西的地区
- This book requires a great deal of concentration. 这本书需要全神贯注才能读懂。
- He is a boy with little power of concentration. 他是个注意不易集中的男孩。
- The nether regions of the earth. 地球底部地区
- He has great powers of concentration. 他注意力很集中。
- His area of concentration is economics. 他专心研究经济学。
- The region of the abdomen surrounding the navel. 脐部围绕肚脐的腹部部位
- The Determination of Concentration for SO_2 Gase. SO_2气体浓度的测定
- An inland or upland region of a country. 一个国家的内陆地区或高地
- It is hard to map all the regions of big countries. 为幅员辽阔的国家绘制地图，想把每个地区都详细标注是件困难的事。
- The regions of space beyond the earth's atmosphere. 太空超出地球大气层的空间区域。
