In windless weather, when you ride your bike quickly, you will feel the wind blowing head-on. At this time, the reference you choose is

"No wind" means that the air is still relative to the ground. Riding fast, you take the ground as a reference, and you move with the car; Then, if you or your car is taken as a reference, the ground and air move backwards relative to you or your car, that is, you will feel the wind blowing head-on, so you feel the wind with yourself as a reference.

Train of thought analysis: The key to solve this problem is to see clearly what the object is being studied, and then choose the reference object according to your own feelings. If the relative position of the wind and itself changes, then the wind is moving.

Question comment: This question mainly examines students' understanding and mastery of the choice of reference objects, the relativity between motion and stillness, and studies the motion state of the same object. If different reference objects are selected, the conclusions can be different, but they are all correct.