题目

— __________?— They're yellow. A . What color are the shorts B . What color is the T-shirt C . What are they D . How much are they 答案：A如图，现有一个圆心角为90°，半径为8cm的扇形纸片，用它恰好围成一个圆锥的侧面（接缝忽略不计），则该圆锥底面圆的半径为（   ）A．4cmB．3cmC．2cmD．1cm