单选题:The underlined word "it" in Paragraph 4 refers to 题目分类:中学英语 题目类型:单选题 号外号外:注册会员即送体验阅读点! 题目内容: The underlined word "it" in Paragraph 4 refers to A.the team B.the gene C.the growth factor D.the brain 参考答案:【答案仅供学习,请勿对照自行用药等】 答案解析: