问答题 尿不湿与啤酒的案例体现的规律是：                                                               。

单项选择题 合同签订以后可以更改内容吗？ A、Our current contract is about to expire, and we’ll need to discuss a new one. B、Shall we draw up a draft of the contract？ C、If everything is satisfactory, we can draw up a formal contract. D、Is it possible to change the details of the contract after it’s made?

单项选择题 清末陕西女首富周莹用“学徒制”的方法留住了人才。