题目

Hundreds of people have formed impressions of you through that little device(装置) on your desk. And they’ve never actually   36   you. Everything they know about you   37   through this device, sometimes from hundreds of miles away.   38   they feel they can know you   39   from the sound of your voice. That’s how powerful the   40   is.Powerful, yes, but not always   41  . For years I dealt with my travel agent only by phone. Rani, my faceless agent whom I’d never met   42  , got me rock-bottom prices on airfares, cars, and hotels. But her cold voic已知：如图，在半径为4的⊙O中，圆心角∠AOB=90°，以半径OA、OB的中点C、F为顶点作矩形CDEF，顶点D、E在⊙O的劣弧AB上，OM⊥DE于点M．试求图中阴影部分的面积．（结果保留π）