其次对这群古老的流星群做了一些新的研究和探讨，得出五项结果，其中活动周期是很值得再研究的一项。

And then, five items of results on these ancient meteors are obtained by some new studies and exploration, in which the period of activity is one merits further study.

youdao

其次对这群古老的流星群做了一些新的研究和探讨，得出五项结果，其中活动周期是很值得再研究的一项。

And then, five items of results on these ancient meteors are obtained by some new studies and exploration, in which the period of activity is one merits further study.

youdao