多长时间

• How long are you in beijing ? （ for ） a long time
  你在北京多长时间了?很久了。
• How long does it take to send the parcel to tokyo
  这个包裹寄到东京要多长时间？
• Because you don ’ t know how long it will take
  因为你不知道等待需要花多长时间。
• How safe and for how long is entirely up to you
  有多安全和多长时间完全由你决定
• " how long ' s this gonna take ? " i asked the flagman
  “要多长时间？ ”我问司旗手。
• How long time will it take for emergency evacuation
  应急疏散到底需要多长时间
• He had no idea how long she had been there
  他不知道她在这里已经有多长时间了。
• How long does it take him to get to america by air
  乘飞机到美国花他多长时间呀？
• How long can you stare without blinking ( your eyes )
  你能瞪著看多长时间不眨眼
• Be a guest in my house for as long as you desire
  在我家里做客吧，随便多长时间