Some add additional materials to the videos or offer ideas for the next segment.

有些人在视频中添加了额外的材料，或者为下一个片段提供了想法。

But he says his group provides additional learning materials about health and water and waste systems.

但他说他的组织还提供了卫生、水和垃圾系统方面的额外学习资料。

I also recommend some additional material that is not contained within the book that you might want to look up if you want to learn more about, basin statistics.

我也推荐一些书中没有包含的额外材料 如果你想了解更多 你可能想要查一下 盆地统计。