One day, Dog was feeling very sad.

Cat saw Dog and asked, 'Why are you sad?'

Dog said, 'I lost my favorite bone.'

Cat said, 'Don't worry, I will help you.'

Cat sniffed the ground and followed the scent.

Finally, Cat found the bone hidden in the bushes!

Dog was so happy! He wagged his tail and thanked Cat.

From that day on, Dog and Cat became best friends.