In doing so they were lifting a rock only to drop on their own feet. 他们这样做，只不过是搬起石头砸自己的脚。
Some men on their own will live out of tins rather than cook meals for themselves. 一些独居的男人宁肯靠罐头食品过日子，也不愿自己烧饭吃。
Many people can answer questions on their own special subject, but it's general knowledge questions that separate the men from the boys. 许多人能够回答他们各自专业方面的问题，但是真正能区别人的智能还是一般常识的问题。
