a jolly dog

例句：

1. 1. The little boy was so happy that he jumped for joy.
   那个小男孩非常开心，他跳了起来。
2. 2.The old man had a jolly dog that would always greet him with a wagging tail.
   那位老人有一只快乐的狗，它会用摇尾巴的方式迎接他。
3. 3.The dog's jolly demeanor made everyone smile.
   这只狗的快乐态度让每个人都笑了。