challenges

例句:

• The secret to happiness is to keep setting yourself new challenges.
  幸福的秘诀就是要不停地给自己设定新的挑战。
  来自柯林斯例句
• Dara challenges our stereotypical ideas about gender and femininity.
  达拉对我们老一套的性别和女性特质观念提出了异议。
  
• The government performed competently in the face of multiple challenges.
  面临多种挑战，政府表现得非常出色。
  
• Mr Swinney said the challenges ahead were not unusual.
  来自BBC
• Modeling brings in a whole different set of challenges.
  来自SA
• Of course, challenges await us at each destination.
  来自WSJ