Question 6 is based on the conversation you have just heard.

6. What does the woman say her shop tries to do？

解析：C。本题目为细节题。问题为：女士说她的商店尝试做什么？原文所在句：Commercially speaking, it’s fairly low, and we try to keep our expenses as low as we can.可见女士尝试尽他们所能降低开支。文章第一个话题是毛收入，第二个话题转向了开支的问题，女士表示在开支方面尝试去尽可能减少。选项C) Keep down its expenses（降低花费开支），与该信息完全一致。其他选项属于无中生有，对话没有提到，因此较好排除。