fly a flag union down

例句：

1. 1.The bird flew over the treetops.
   那只鸟飞过了树梢。
2. 2.The butterfly is flying around the garden.
   这只蝴蝶正在花园里飞舞。
3. 3. The plane was flying high above the clouds.
   飞机正高高地飞在云层之上。