sentence2_structure: The human penis<>contains<>the urethra, as well as three cylinders of spongy erectile tissue
sentence1: Penis The penis is composed of three cylindrical bodies of spongy cavernous tissue, bound together by connective tissue and loosely covered by a layer of skin.
sentence2: The human penis contains the urethra, as well as three cylinders of spongy erectile tissue.
question: The human penis contains the urethra, as well as how many cylinders of spongy erectile tissue?