What jokes are there that are even funnier when you think about them?

1. In the music class, the teacher played a Beethoven tune. Xiaoming asked Xiaohua, "Do you know music?" Xiaohua: "Yes." Xiaoming: "Do you know what the teacher is playing?" Xiaohua: "Piano."

2. Triangle, square and circle meet to go shopping, and the circle and square come, but the triangle doesn't. What is this situation called? Congruent triangles.

3. One day, Xiaomei and her boyfriend went out for a ride. The car is running out of gas, and there is a gas station next to it. When driving by, a sudden gust of wind blew my boyfriend's hat away. Xiaomei's boyfriend said to her, "I'll get my hat and you help me refuel." Just after her boyfriend ran away, she heard Xiaomei shouting behind her: "Come on! Come on! "

One day, the toothpick was walking and found that the shoelace was open, so I bent down to tie it, and then my waist broke.