The sun walks round and round o_____ the earth day and night.

orbiting 围绕...的轨道运行

相关参考：

orbit: [ 'ɔ:bit ]

n. 轨道,常轨,眼眶
v. 绕轨道而行,进入轨道,盘旋

词形变化:
动词过去式:orbited 过去分词:orbited 现在分词:orbiting 第三人称单数:orbits

例句与用法:
1. The spacecraft is in orbit around the moon.
该航天器在绕月球轨道运行。

2. How many spacecrafts are orbiting the moon?
有多少航天器绕月球轨道飞行？

3. How many satellites have been put into orbit round the earth?
有多少颗人造卫星已送入绕地球轨道?

offering

orbitting

orbiting

over

个人觉得