What do you think is the reason why Tang Monk shivered on his horse?

Cold weather, psychological effects, and physical weakness.

1. The weather is cold: Tang Seng felt the cold on his horse, so he shuddered.

2. Psychological effect: Tang Seng will feel nervous and scared because of certain things immediately, which will cause the body to have a stress reaction and shiver.

3. Physical weakness: Tang Seng was physically weak on horseback and was easily affected by the external environment, resulting in chills.