Plant Self-defense Plants may appear to be helpless in the face of hungry,toothy animals but many plants have evolved interesting systems of self-defense. Coarse meadow grasses are a good example. If you run your finger along a blade of coarse grass,

发表于:2018-12-31 / 阅读(44) / 评论(0) 分类 英语听力文摘 English Digest

图片 by Jason Marshall Some math is functional. Some math is fun. And some math is simply stunning. If that last description sounds improbable to you, then today just might change your mind. Because now that weve covered enough ground, were going t

发表于:2019-01-02 / 阅读(115) / 评论(0) 分类 数学英语

AS IT IS 2015-07-14 Silica Sand Mining Worries Communities 美国硅砂矿引发社区担忧 The United States is increasing production of oil and natural gas through a process known as fracking. This process is sometimes called hydraulic fracking be

发表于:2019-01-12 / 阅读(65) / 评论(0) 分类 2015年VOA慢速英语(七)月

AILSA CHANG, HOST: Despite mounting evidence and a stream of dire warnings, federal regulators and mining companies failed to protect coal miners from toxic dust. MARY LOUISE KELLY, HOST: NPR and the PBS series Frontline spent more than a year lookin

发表于:2019-01-19 / 阅读(55) / 评论(0) 分类 2018年NPR美国国家公共电台12月

BEIJING, May 13 (Xinhuanet) - China's central bank announced on Saturday it would lower the reserve requirement for commercial lenders by 50 basis points, the second time it has taken such action this year to inject more market liquidity and shore up

发表于:2019-02-04 / 阅读(82) / 评论(0) 分类 英语新闻

Senem: Hey, Shawn, I heard that you are really good at making key lime pie. Shawn: Key lime pie, that's my special recipe. I just can't give that out to anybody. Senem: Yes, you can. Please. I really want to make it tonight. Please tell me. Shawn: Wh

发表于:2019-02-17 / 阅读(63) / 评论(0) 分类 英语访谈对话