The planet also began releasing oxygen, thanks to an ancient adoption of photosynthesis. A very ancestral primitive plant cell either engulfed or tried to digest or surrounded a cyanobaterium and instead of digesting it, it actually became an organ w

发表于:2019-01-23 / 阅读(50) / 评论(0) 分类 探索与发现2014年

 Superglue 强力胶 Male: Help!Help! Female:What's wrong? M: I was fixing my coffee cup with superglue .And I must have got some on my fingers but I scratch my forhead.And now my hand is stuck to my head. F: Superglue ? Cool! What makes supergl

发表于:2019-01-26 / 阅读(47) / 评论(0) 分类 英语听力文摘 English Digest

On its website, a history of the company makes no mention of leador indeed of Thomas Midgleybut simply refers to the original product as containing a certain combination of chemicals. 在它的网站上,公司的历史没有提及铅──也没有提

发表于:2019-02-17 / 阅读(53) / 评论(0) 分类 万物简史

By counting back through these layers and measuring the amount of lead in each, he could work out global lead concentrations at any time for hundreds, or even thousands, of years. The notion became the foundation of ice core studies, on which much mo

发表于:2019-02-17 / 阅读(59) / 评论(0) 分类 万物简史

Lead is a neurotoxin. Get too much of it and you can irreparably damage the brain and central nervous system. Among the many symptoms associated with overexposure are blindness, insomnia, kidney failure, hearing loss, cancer, palsies, and convulsions

发表于:2019-02-17 / 阅读(53) / 评论(0) 分类 万物简史

If you were going to a restaurant and wanted a healthier option, 如果你去饭店,你想吃得健康一点, which would you choose, grilled or fried chicken? 你会选择哪种食品呢,烤鸡还是炸鸡? Now most people would answer grill

发表于:2019-02-21 / 阅读(68) / 评论(0) 分类 TED演讲教育篇