【简答题】10 设有两种报警系统Ⅰ与Ⅱ,它们单独使用时有效的概率分别为 0.92 与 0.93 ,且已知在系统Ⅰ失效的条件下,系统Ⅱ有效的概率为 0.85 ,求:系统Ⅰ与Ⅱ同时有效的概率?
【单选题】A society cannot be successful if it throws tradition away,but it cannot be successful ________ if we do something to stop progress. (2013·福建,35)
【单选题】People from all over the world ________ China on the successful launch of Chang’E-1.
【单选题】The successful launch of Chang'e II _____ everyone involved in the space project making an effort. [ ]
【简答题】听力原文:What will the successful applicant be paid? What will the successful applicant be paid? Top London rates and provided with______.