2014年4月24日
Cows
摘要： Farmer John's cows have discovered that the clover growing along the ridge of the hill (which we can think of as a one-dimensional number line) in his... 阅读全文
posted @ 2014-04-24 13:19 daydaycode 阅读(437) 评论(0) 推荐(0) 编辑