míng / cháo / shí / qī / ， / Wǎ / là / shì / běi / fāng / biān / jìng / de / zhòng / yào / yóu / mù / shì / lì

明朝时期，瓦剌是北方边境的重要游牧势力。

During the Ming Dynasty, the Oirat Mongols were an important nomadic power on the northern border.