doubling ['dʌblɪŋ]

例句:

• A violinist anxious to learn a 'doubling instrument'.
  来自Melody Maker
• He is doubling the parts of a preacher and a teacher.
  他扮演传道人和教师两个角色.
  
• You've then got an evens chance of doubling your money at a stroke.
  然后你就有一半的机会可以把钱一下子翻一倍。
  
• He's doubling the parts of a servant and a farm worker.
  他既当仆人又做农工.
  
• Doubling our solar capacity every year is pretty good.
  来自SA
• You're talking about nearly doubling the greenhouse-gas emissions.
  来自NEWYORKER