A:It's next to the hospital.
B:There is a cinema.
—______you study at home in 100 years?
—Yes, I______.
如图,AB为⊙O的直径,CD为⊙O的一条弦,CD⊥AB,垂足为E,已知CD=6,AE=1,则⊙0的半径为____.
读“中国地形示意图”回答下列问题。