题目

给出下列图形：①角；②线段；③等边三角形；④圆；⑤正五边形．其中属于旋转对称图形的有__________，中心对称图形有________．(填序号) 答案： ②③④⑤       ②④23.[2000春季全国] The changes in the city will cost quite a lot, ________ they will save us money in the long run. A. or B. since  C. for D. but