题目

阅读理解 The earliest known copy of Leonardo da Vinci's MonaLisa—thought to have been painted at the same time as the originalmasterpiece—has been discovered at the Prado Museum in Madrid, Spain. The workoffers art-lovers an attractive clue to what the model for the world's mostfamous painting really looked like. Controllers of the museum found the picturehidden beneath layers of paints during restoration work on a picture initiallythought to have been a later replica(exact copy) of the Mona Lisa. The restored version shows the same woman that Leonardodepicted (描画),against a landsc一个圆柱体的侧面展开图是一个正方形。这个圆柱底面直径与高的比是A．1：πB．1：2πC．1：4πD．2：π