left behind [lɛft bɪˈhaɪnd]

例句:

• Once the eggs have hatched the shells are left behind.
  一旦鸡蛋孵化后，蛋壳就没用了。
  来自柯林斯例句
• They are left behind, often with ageing relatives.
  来自BBC
• It is wrong to have left the deaf behind.
  来自BBC
• But the picnickers left behind litter and leftover food.
  来自BBC
• I got left behind at school with the maths.
  在校时我的数学跟不上。
  
• We're going to be left behind by the rest of the world.
  我们将被全世界甩在后面。