循环的英文：
circle
loop
circulate

• The seasons rotate.
  四季循环。
• loop initialization
  循环初置(初始状态的),循环初始化
• The backwater recirculates
  回水是反复循环。
• The refrigerant in a household refrigerator also undergoes a cyclic process
  家用冰箱的致冷剂，也经历循环过程。
• Exercise helps the blood and other body fluids to circulate.
  锻炼帮助血液和其它体液循环。
• The last figure of the decimal 0.63 repeats.
  小数0.63的末位数是循环的。
• Although oxygen does not participate directly in the citric acid cycle, the cycle operates only when O2 is present.
  尽管氧气没有直接参与三羧酸循环，循环却只有在氧气存在时才能进行，
• This material is recyclable and will not pollute the environment.
  这种材料是可循环利用的，因而不会污染环境。
• Oxaloacetate is formed in the last step of the citric acid cycle by the NAD+-dependent oxidation of L-malate.
  草酰乙酸在三羧酸循环的最后一步通过NAD+-依赖的L-苹果酸的氧化来合成。
• "Wet beriberi is more acute, with edema from cardiac failure and poor circulation."
  湿性脚气病病情较急，会有心力衰竭、循环不良及主要由此造成的水肿。

• circle of longitude
  经度圈;经度圈;黄经圈;黄纬圈
• circle of declinatio
  赤纬度盘;赤纬圈;时圈
• This is a chord of a circle.
  这是个圆的弦。

• The airman looped the loop eight times.
  那位飞行员作了八次翻筋斗的飞行表演。
• The plane looped the loop three times.
  飞机连翻了三个跟头。
• Loop the tree with a rope = loop a rope around the tree
  将绳子卷绕于树

• Have you been circulated with details of the conference?
  你收到会议详情的通知了吗？
• circulate counterfeit coins
  使伪造的钱币流通
• This magazine has a large circulation.
  这本杂志发行量很大。