未知题型 利用贪心法求解0/1背包问题时，(55)能够确保获得最优解。用动态规划方法求解 0/1背包问题时，将“用前i个物品来装容量是X的背包”的0/1背包问题记为KNAP(1,i,X)，设fi(x)是KNAP(1,i,X)最优解的效益值，第j个物品的重量和放入背包后取得效益值分别为 wj和pj(j=1～n)。则依次求解f0(x)、f1(x)、...、fn(X)的过程中使用的递推关系式为(56)。.A．优先选取重量最小的物品B．优先选取效益最大的物品C．优先选取单位重量效益最大的物品D．没有任何准则

单项选择题 听力原文：M: Excuse me. Would you happen to know where the post office is? I was told that it was around here somewhere, but I can't seem to find it. W: The post office you're looking for used to be right here next to the stationery store, but it moved to the corner of Sunset Road and Elm Street a couple of weeks ago. If you want to go there, just walk straight down this road until the next intersection. Turn right, and walk two blocks until you see the brown building on the northwest corner. M: Thanks a lot. And, would you happen to know what time it closes, by the way? I heard the closing time is at 4 o'clock. W: As far as I know, they're open until 4:30. Yes, I'm sure they are open now. I was there the other day, and t remember looking at my watch. It was 4:20 at the time.Where is the conversation taking place?A．In a stationery store.B．In a post office.C．On a street.D．At city hall.

未知题型 关于施工质量计划，下列说法正确的是（ ）。－－P182