When I was a child, I played with 1988' s younger brother in the kindergarten yard. There were only three children at that time. Suddenly, I saw a small plane 30-40 cm long flying towards us. The small plane looks complete, and the most important thing is to fly flexibly. It flew twice over our heads, deliberately flying two meters above our reach. It seems to be playing with us. We immediately went to find a bamboo pole to smash it, but when we found it, it was amazing. I still can't figure out what he is At that time, the model airplane was not so advanced!