1, there are fewer suppliers, especially in the north and winter, the production and reproduction costs are relatively high, and the customer acceptance is not high.

2, the risk of flying activities is relatively high, and indoor flying may cause pollution to banquet food. Do harm to children who are chased by curiosity.

3, sorry. Become a butterfly is the tragic story of butterfly, and Liang Zhu's love. Married couples and their elders are still more willing to grow old together than to fly together.