许多古代文明，比如埃及或美索不达米亚文明，都起源于大河流域。

Many ancient ___civilizations, like those of Egypt or Mesopotamia, arose around major rivers.

现代社会高度重视公共讨论中礼貌与尊重的原则。

Modern ___civilization places a high value on the principles of politeness and respect in public discourse.

科技的飞速发展是我们当代文明的一个标志。

The rapid progress in science and technology is a hallmark of our contemporary ___civilization.