单项选择题 某水坝工程可以满足各种功能要求的方案有A和B两个：A方案的建造费用为1000万元，每年的运行及维护费用为150万元；B方案的建造费用为1500万元，每年的运行及维护费用为100万元。两个方案的寿命期皆可以看作为无限年。设贷款的利率为5％。A、B两方案的差额年值为（ ）万元。

未知题型 The biggest computer company in Silicon Valley has laid off hundreds of people during the last few years.A.declinedB.detachedC.dismissedD.dispersed

未知题型 Fictory and accompanying prosperity muted memories of the Great Depression and made him a national hero.A.transpireB.upbraidC.muffleD.twist