At the same time, a stable and reasonably advanced agriculture began to develop to the east of the frontier. Gradually, a commercial agriculture developed.

同时，边疆东部开始形成稳定且相对进步的农业，商业化的农业也逐步形成。

youdao

Influenced by different opinions of the nature of frontier wars in the Tang Dynasty, people have different comments all the time on the theme value of the frontier fortress poems of the Tang Dynasty.

受唐代边境战争性质不同认识的影响，人们历来对唐代边塞诗的主题价值有不同的评论。

youdao

If an earlier generation was preoccupied with the quest to enclose a vast geographic frontier, the dotcom generation, it seems, is more caught up in the colonization of time.

如果说人们在较早的时代全神贯注于获取辽阔的地理边界，在网络公司时代人们则似乎更忙于时间殖民化。

youdao

Mackinder saw history being made on the Northwest frontier of India, but the Empire bled to death on the fields of France in fear of what might happen elsewhere, and by the time it got to India it handed over that frontier, out of exhaustion and a growing reluctance to fight for a possession that did not want to be possessed.

NEWYORKER: Faces, Places, Spaces

The risk and return components of the efficient frontier are computed for a specific time period, usually one year.

FORBES: The Efficient Frontier