maintain

• U.s. agriculture must maintain its technological leadership .
  美国农业应保持其技术上的领先地位。
• They maintain a very powerful fleet in oriental waters .
  他们在远东海域保持着一支非常强大的舰队。
• Enough electrons are present to maintain electrical neutrality .
  存在着足够多的电子以维持电中性。
• A due watchfulness on the movements of the enemy was maintained .
  他们对敌人的行动还是相当警惕的。
• We would maintain the world balance of power at all costs .
  我们将不惜一切代价维持世界力量的均势。
• Popeye maintains an aloof and superior attitude to the court .
  波普叶对法庭保持一种冷淡、傲慢的态度。
• Exact perpendicularity between the components must be maintained .
  各分量之间必须严格地保持互相垂直。
• It would be designed to maintain incentives for work .
  应该制定这项计划以便保持对人们寻找工作的促进。
• We would surely see to it that the military balance was maintained .
  我们肯定保证要使军事平衡得到维持。
• He had moments of sanity, but he couldn't maintain the balance .
  他也有心智正常的时候，但不能持续多久。