练习时光：
George: Can I help you?
乔治：我能为您效劳吗？
Helen: Yes, I'm doing some research on Roman civilization. Do you have any books on the subject?
海伦：我在做一些关于罗马文明方面的研究，这方面有没有什么书？
George: These books over here are about ancient history. They might be helpful.
乔治：这里的这些书是关于古代历史的。可能有些帮助。
Helen: Can I check this one out?
海伦：这本可以外借吗？
George: I'm sorry. It's for reference only, so it must stay in the library. But you're welcome to look through it.
乔治：对不起，这本只是参考书，不能外借。但是你可以查阅。
Helen: Ok. And I'd like to check these books out.
海伦：好吧。我想借这些书。
George: All right. They're due back next Wednesday.
乔治：好的。归还期限是下个星期三。
Helen: Thanks for your help.
海伦：谢谢你的帮忙。