《北史·本记·卷十二》
秋天，大水灾，山东、河南被水冲没三十多郡，民众争相卖给人当奴婢。
秋，大水，山东、河南漂没三十余郡，民相卖为奴婢。
In autumn, there was a great flood, and more than 30 counties in Shandong and Henan were flooded, and the people vied to sell themselves as slaves.
<s>[INST] Kindly elucidate the central themes in this passage in English: 秋，大水，山东、河南漂没三十余郡，民相卖为奴婢。 [/INST] In autumn, there was a great flood, and more than 30 counties in Shandong and Henan were flooded, and the people vied to sell themselves as slaves.</s>
Kindly elucidate the central themes in this passage in English: 秋，大水，山东、河南漂没三十余郡，民相卖为奴婢。
user
In autumn, there was a great flood, and more than 30 counties in Shandong and Henan were flooded, and the people vied to sell themselves as slaves.
assistant