Joke: brain teaser.

1. I went home two days ago and saw several scratches on my dad's face, which had just scabbed. Out of concern, I asked what was going on. Dad vaguely said that he hit the door, and the mother next to him proudly said, I am the door. (joke)

2. I wrote a math problem in the afternoon at home, and my father came to me kindly. "You are tired of reading math all afternoon." I thought I could play happily. "Well, I'm tired!" "Oh, then relax in another language." (joke)

3. Colleague said: "I also gave a gift to the leader. Why are you still picking on me? " ? I said, "What did you send? When was it sent? " ? Colleagues said, "Tomb-Sweeping Day, send ingots. (joke)

There are two unevenly distributed incense, and the burning time of incense is one hour. What method can be used to determine the time of 15 minutes? (puzzle)

Answer: ignite one end and the item ignites both ends. By the time incense B burned out, it was already 30 minutes. Then ignite the other end of incense A, and the time from this time to burning A is 15 minutes.

5. What is universal? (brain teaser)

Answer: Telephone.

Analysis: The telephone is used all over the world.