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。
I can resist everything except temptation.
你每花一块钱购买一些实质性的东西,预计在其寿命结束时要支付一块钱的维修、保养或处理费用。
合理安排时间就是节约时间。
"The world breaks everyone, and afterward, many are strong at the broken places."
"The historian is a prophet looking backwards."
Science is a tool for empowerment, not control.