maintain

• How do the populations maintain this homeostasis ?
  种群如何能维持这种内稳定状态呢？
• Maintaining adequate grain stocks is expensive .
  维持足够的谷物储备，代价是昂贵的。
• Engineers maintain the turbines .
  机修工维修涡轮机。
• Utility companies could install and maintain them .
  公用事业公司可以安装并保养它们。
• Our model is easy to operate and maintain .
  我们这个型号（的机器）很容易操作和保养。
• The spacing is maintained constant .
  格距保持不变。
• I maintained that it was wrong .
  我认定这是错的。
• The united nations maintains a military presence in the area .
  联合国在该地区驻有军队。
• He was adept at maintaining a psychological advantage .
  他是善于保持一种心理上的优势的。
• The king maintained order within the bound of his realm .
  国王在王国边界之内维持着秩序。