重点讲解：
the least
（应该做的）最少量，最低程度；
eg. Well, the least you can do, if you won't help me yourself, is to tell me where to go instead.
你自己要是不帮我，好歹也告诉我该上哪儿去呀。
eg. The least they could have given me was half a day to rest.
他们本应该起码给我半天时间休息。
eg. The least his hotel could do is provide a little privacy.
他的酒店至少应该提供一点隐私保护。
注：that's the least that I can do，表示，“这是我最起码能做的；我乐意效劳”；
eg. Why not relax and let me teach you how to windsurf? It's the least I can do.
干吗不轻松一下，让我来教你玩帆板？我乐意为你效劳。
eg. I want to help — it's the least I can do for the girl who saved my brother.
我想要帮忙——这姑娘救了我弟弟一命，这是我最起码能做的。