题目

阅读理解 In the 19thcentury, British railways were built from big cities to seaside towns. For thefirst time, working-class people could visit the seaside. They usually took daytrips on Sundays and special days like Easter. Traditionally, people sat on thebeach, swam in the sea, and ate fish. Children could watch puppet (木偶) shows and play onthe beach. In the I950s, thefirst package holidays(包价旅游) were sold. From the 60s to 70s, more and more British people beganto give up the traditional seaside holiday and choose sunshine and warmer seasin countries like Spain and Greece. Cam如图，正方形ABCD边长为4，以BC为直径的半圆O交对角线BD于E．则直线CD与⊙O的位置关系是    ，阴影部分面积为（结果保留π）    ．