题目

Failure is probably the most fatiguing (令人疲劳的)experience a person ever has. There is nothing more tiring than not succeeding, being blocked, not moving ahead. It is an evil circle. Failure causes fatigue, and fatigue makes it harder to get to work, which adds to the fatigue.     We experience this tiredness in two main ways: start-up fatigue and performance fatigue. In the former case, we keep putting off a task that we are forced to take up. Either because it is too boring or because it is too difficult, we avoid it. And the longer we put it off, the more tired we feel.    Su如图，某房间的地面形状是△ABC，DE是地面上的一条装饰线，且DE∥BC，，一只小猫在此房间内随意走动，当它停下来，又恰好停在四边形BCED内的概率是________．