【简答题】We may think we&39;re a culture that gets rid of our worn technology at the first sight of something shiny and new, but a new study shows that we keep using our old devices(装置) well after they go out ...
【单选题】Our music teacher has won the first prize in the competition. We’re very _______ him.
【简答题】证明:函数组x 3 ,x 3 +x,x 2 +1,x+1是F[x] 3 的一个基,并求f=x 2 +2x+3在该基下的坐标.
【单选题】Our monitor has won the first prize in the competition. We're very ______ him. [ ]
【判断题】口罩被患者血液、呼吸道 / 鼻腔分泌物,以及其他体液污染要立即更换。
【判断题】口罩被患者血液、呼吸道、鼻腔分泌物污染后,立即更换
【简答题】用计算机随机产生的有序二元数组(x,y),满足-1<x<1,-1<y<1,对每一个二元数组(x,y),用计算机计算x 2 +y 2 的值,记A为事件“x 2 +y 2 >1”,则事件A发生的概率是______.