无忧无虑者

例句：

1. 1. He was so worried about the exam that he couldn't sleep last night.
   他因为考试而非常担心，以至于昨晚睡不着。
2. 2. She felt worry-free after her successful surgery.
   她手术成功后感到无忧无虑。
3. 3. The couple is worrying-free because they have a good relationship.
   这对夫妇无忧无虑，因为他们关系很好。