definition of planet meaning in English

行星的定义
行星定义

The definition of planet is not only a science issue , but also a social issue
行星的新定义不单是科学问题，也是社会问题。
When i was heading to hungary by train after the assembly , two english girls sitting next to me discussed the new definition of planet . while they felt somewhat confusing , i am glad that they now know that there are eight planets in our solar system
在大会结束后乘火车前往匈牙利的途中，邻座两位英国少女正讨论行星的新定义，虽然她们觉得有点混乱，但我很高兴她们已了解到太阳系只剩下八大行星。