题目如图,ABABAB是⊙O\odot O⊙O的直径,点CCC,DDD,EEE在⊙O\odot O⊙O上,若∠AED=18∘\angle AED=18^{\circ}∠AED=18∘,则∠BCD\angle BCD∠BCD的度数为( )A.70∘70^{\circ}70∘B.36∘36^{\circ}36∘C.54∘54^{\circ}54∘D.72∘72^{\circ}72∘知识点:切线的性质章节:图形的性质 / 圆