Students care about each other after falling down.

Classmate, the angle between you and the ground just now was 75 degrees, so you fell down. If you lean on crutches, you can form the most stable iron triangle with the ground.

Classmate, your hiking shoes are not suitable for walking smoothly. Although your shoes are uneven, the contact area with the ground is too small, and your boots are better.

Classmate, you knocked your head off. If you wear a hat from the beginning, according to chaos theory and butterfly effect, you will still fall, but your head will not be hurt.

Classmate, your pants are dirty and stained with blood. Look, look, they are still running. In view of cotton hemostasis, red is easier for you to be recognized, and it is safer to wake up the driver in advance. You can wear a red cotton-padded jacket to resist falling.

So, the next day, there was another Santa Claus in the class.