轻度灰化土

For those of us lucky enough to always have enough food and water, it may be hard to imagine living through a drought. A drought occurs for a variety of reasons, usually including a lack of rainfall and warm temperatures.Soil moisture severely dwindl

发表于:2019-01-26 / 阅读(62) / 评论(0) 分类 英语听力文摘 English Digest

Topics: Ask an American: driving while texting; ground versus soil versus land; as such; pupil versus people Words: eyewitness report to lose control apparent median to clip to flip distraction visual to glance manual cognitive to take (ones) mind of

发表于:2019-02-23 / 阅读(38) / 评论(0) 分类 美语听力 English Cafe

Don: Hey, Yael, Have you heard? We've discovered two new oceans? Yael: Where? D: On Mars. Well, they aren't there any longer, but they were there a few billion years ago. Y: I thought scientists weren't sure if Mars had oceans or not. D: They weren't

发表于:2019-02-24 / 阅读(36) / 评论(0) 分类 英语听力文摘 English Digest

Toxin-loving Trees 树木能调节气候,保持生态平衡,树木通过光合作用,吸进二氧化碳,吐出氧气,使空气清洁,新鲜。一亩树林放出的氧气够65人呼吸一辈子。树还能防风固沙,涵养水土,吸收各种粉

发表于:2019-02-24 / 阅读(135) / 评论(0) 分类 英语听力文摘 English Digest

How Rocks Appear In Your Garden 岩石,是在地质作用下形成的矿物聚合体,其中海面下的岩石称为礁、暗礁及暗沙,由一种或多种矿物组成的,具有一定结构构造的集合体,也有少数包含有生物的遗骸

发表于:2019-02-24 / 阅读(49) / 评论(0) 分类 英语听力文摘 English Digest

Sugar bowls and hole 孔隙是岩土固体矿物颗粒间的空间。岩土中直径大于1毫米、重力水可于其中自由运动的孔隙,是大孔隙(macro-pore,large pore)。岩土中直径为0.01~1毫米、重力水和毛管水可存其

发表于:2019-03-09 / 阅读(86) / 评论(0) 分类 英语听力文摘 English Digest