Peter: Let's play computer games!
Barry: That sounds interesting, but I don't have a computer.
Peter: Well, do you have a volleyball?
Barry: Yes.
Peter: Then let's play volleyball.
Barry: Oh, volleyball is so difficult.
Peter: OK, let's watch TV.
Barry: That sounds boring. Hmmm, let's play soccer! Do you have a soccer ball?
Peter: No, I don't.
Barry: Oh, well, do you have a basketball?
Peter: Yes, I do. Let's play basketball!
Barry: That sounds fun!

阅读下列材料：

   “中世纪时，欧洲百姓大都不识字，只有教士具有一定文化知识……随着财富和势力的增加，教会成为封建制度的精神支柱，教会上层人物日益腐化堕落。”

请完成：

材料一：中华开国五千年，神州轩辕自古传。创造指南针，平定蚩尤乱。世界文明，唯有我先。

——孙中山

材料二：“尧知子丹朱之不肖，不足授天下，于是乃权授舜。授舜，则天下得其利而丹朱病；授丹朱，则天下病而丹朱得其利。尧曰：终不以天下病而利一人。”

——《史记五帝本纪》

制作泡菜的原理是利用（  ）进行发酵