—— 请按键盘 空白键 开始游戏 ——

Science thrives on doubt and skepticism.
I’ve never been a person that has been concerned about what people say. I’m just me.
人为某样东西实际支付的成本至少是标价的两倍,因为买来后设置、学习、维护、修理,以及最后处置,也需要耗费精力、时间和钱。不是所有的实际成本都在价签上。实际成本是标价的2倍。