燕卷尾

例句：

1. 1.The swallow's tail is a distinctivefeature of its flight pattern.
   燕子的尾巴是其飞行模式的独特特征。
2. 2. The swallow's tail helps it to hover inmid-air.
   燕子的尾巴帮助它在空中悬停。
3. 3. The swallow's tail isused for communication with other birds.
   燕子的尾巴用于与其他鸟类的交流。