题目

— Is there anything else you want to know about China?— Yes, I am still wondering _________. A. how is the Chinese paper cut made             B. why the Chinese people like to play the dragon dance(舞龙)    C. how was the Great Wall built in ancient time D. why do the Chinese people eat rice dumplings at Dragon Boat Festival 答案：B如图，圆是的外接圆，过点C的切线交的延长线于点，，。则的长______________，的长______________．