乐滋滋的

例句：

1. 1. She is very happy to receive the gift from her friend.
   她收到朋友的礼物时非常开心。
2. 2. The children were all overjoyed at the news of their parents' return.
   孩子们听到父母回来的消息都非常高兴。
3. 3. He was so delighted with the success of his project that he couldn't help but smile.
   他对项目的成功感到如此高兴以至于忍不住笑了。