关系模型基于谓词逻辑和集合论，为数据库管理提供了坚实的数学基础。

"We must challenge the status quo and constantly seek better ways to do things."

"Every story is two stories - the one on the surface and the one hidden beneath."

Every reader is a potential writer, and every writer is a reader in revolt.

手工制造一支这样的枪所需的劳动会耗尽任何普通工匠的耐心和毅力。