摘要: Cow Pedigrees Farmer John is considering purchasing a new herd of cows. In this new herd, each mother cow gives birth to two children. The relationshi 阅读全文
posted @ 2016-10-03 08:33 sigongzi 阅读(542) 评论(0) 推荐(0) 编辑
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posted @ 2016-10-03 08:19 sigongzi 阅读(7) 评论(0) 推荐(0) 编辑