乙醯溴乙酸乙酯

美科学家研发新一代驱蚊剂 In many regions of the world, mosquitoes are a seasonal pest. In other regions, they carry serious diseases like malaria. The World Health Organization estimates that almost 630,000 people died of malaria-related

发表于:2018-12-19 / 阅读(61) / 评论(0) 分类 VOA双语新闻 2014年1月

The Zhenjiang vinegar is made from sticky rice. 镇江香醋的原料是糯米 Production starts with soaking the sticky rice. 浸泡过的糯米经过高温蒸煮 The rice is first steamed in high temperatures until the starch component gets sticky.

发表于:2018-12-28 / 阅读(58) / 评论(0) 分类 舌尖上的中国第一季

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