选择题:A.π/6 B.π/4 C.π/3 D.π/2 题目分类:土木工程师(水利水电) 题目类型:选择题 号外号外:注册会员即送体验阅读点! 题目内容: A.π/6B.π/4C.π/3D.π/2 参考答案: 答案解析: