题目奶牛产奶量达一生中最高峰是6~9岁时,即第( )A. 4-7胎B. 5-8胎C. 9-10胎奶牛产奶量达一生中最高峰是6~9岁时,即第( )A. 4-7胎B. 5-8胎C. 9-10胎题目解答答案A. 4-7胎