答:蛔虫的成虫分雌、雄二种。雌虫较粗大,体长约20～40厘米,粗约5～6毫米;雄虫较小,体长约15～30厘米,粗约3毫米。虫体的大小与被寄生者的营养状况有关,当营养状况较差、寄生的蛔虫数多时,虫体较正常为小。雌虫的子宫内充满虫卵,约 A: Roundworm adult female, male two. Female larger, body length of about 20 to 40 cm, roughly 5 to 6 mm thick; male smaller, body length of about 15 to 30 cm, about 3 mm thick. The size of the parasites is related to the nutritional status of the parasites. When the nutritional status is poor and the number of parasitic roundworms is long, the parasites are smaller than normal. Female uterus filled with eggs, about