upper Pleistocene series

例句：

1. 1.The upper Pleistocene series is the most important part of the fossil record.
   更新世系是化石记录中最重要的部分。
2. 2. The upper Pleistocene series contains many species that are now extinct.
   更新世系包含了许多现在已经灭绝的物种。
3. 3. The upper Pleistocene series is a valuable resource for studying Earth's climate and environment.
   更新世系是研究地球气候和环境的重要资源。