Xiaohong traveled to Mount Tai and sat on the sightseeing cable car. She felt that the surrounding scenery was retrogressive, so she chose this as a reference. I feel chest tightness when I get to the

Xiaohong traveled to Mount Tai and sat on the sightseeing cable car. She felt that the surrounding scenery was retrogressive, so she chose this as a reference. I feel chest tightness when I get to the top of the mountain. (1) Sitting on the sightseeing cable car, taking the cable car as a reference, the position between the surrounding scenery and the cable car has changed, and the scenery is moving, so we feel that the surrounding scenery is moving backwards during the cable car sightseeing;

(2) The air pressure decreases with the increase of height, so Xiaohong feels chest tightness when she reaches the top of the mountain.

So the answer is: cable car (Xiaohong himself, etc. ); Small.