unachievable [ˌʌnəˈtʃi:vəbl]

例句:

• To Ackerley, he was an image of unachievable virility and spiritual waste.
  来自NEWYORKER
• This goal, however, looks increasingly distant and unachievable in today's Taiwan.
  但这在现阶段的台湾似乎已经成了一个日渐遥远、甚至遥不可及的奢望.
  
• The prevalence of such values has made boosting the national birthrate seem an unachievable goal.
  也正因为这种价值观念,使得人口增长成了一个遥不可及的目标.
  
• The program was behind schedule, over budget, and unachievable.
  来自NEWYORKER
• We need to stop promoting this image of a perfect body which is unachievable.
  来自BBC