Who can tell some funny jokes? Thank you!

An China, an American and a Japanese were in the same boat, and the boat ran aground. Three men came to an isolated island and met a cannibal. The leader said, "each of you find five round things, or you will be eaten." China took five grapes and came back first. The leader said, "Eat them." People in China eat grapes. The leader said, "You can go." The American brought back five walnuts, and the leader said, "Eat." Americans put walnuts in their mouths, and their mouths hurt to death, but they still smiled. The leader asked him, "What are you laughing at?" The American replied, "I saw the Japanese picking durian."