2018年5月27日
Open-Pit Mining
摘要： DescriptionOpen-pit mining is a surface mining technique of extracting rock or minerals from the earth by their removal from an open p... 阅读全文
posted @ 2018-05-27 22:14 StarHai 阅读(429) 评论(0) 推荐(0)
Multiplication Game
摘要： DescriptionAlice and Bob are in their class doing drills on multiplication and division. They quickly get bored and instead decide to ... 阅读全文
posted @ 2018-05-27 22:09 StarHai 阅读(400) 评论(0) 推荐(0)