while

• A policeman must not smoke while he is on duty .
  警察当班值勤时不得抽烟。
• What have you been doing all the while ?
  你这一向干了些甚么呀？
• To be agreeable while disagreeingthat's an art .
  强颜欢笑，是一种艺术。
• Horses should be walked for a while after a race .
  马在比赛后应该遛一遛。
• He was too intent, while too uncertain .
  他太热切了，反倒变得手足无措了。
• No harm shall come to you while i stand by .
  只要我在这里，决不让你受苦。
• After a while he started to doze .
  过了一会儿，他便鼾声大作了。
• Come, drink your new milk while it is warm .
  好吧，把鲜牛奶趁热喝下去吧。
• Hold the line while i see if she is here .
  请别挂断电话，我去看她在不在。
• He stayed with the doctor quite a while .
  他跟着郎中过了相当长的一段时间。