As a kindergarten teacher might say, sharing is caring. She might not mention that cooperation is also a great way to form a community and thus improve everyone's chances of survival. Humans aren't only ones to apply this strategy. Marine bacteria al

发表于:2018-12-24 / 阅读(32) / 评论(0) 分类 Scientific American(九)月

[00:01.84]3 Listen and complete. [00:06.70]What have the children done for their project [00:10.30]on population? [00:11.96]Listen and complete their sentences. [00:16.14] [01:04.64]4 Listen and complete. [01:08.78]Listen and fill in the missing info

发表于:2018-12-29 / 阅读(96) / 评论(0) 分类 外研社新标准初中英语九年级

This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute. Theres definitely methane on Marsand there are seasonal variations of how much is being released into the thin Martian atmosphere. Which means that Mar

发表于:2019-01-08 / 阅读(53) / 评论(0) 分类 Scientific American(一)月

This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute. Mosquitoes carry nasty diseasesdengue fever, west nile, malaria. But the microbes that cause those diseases dont attach themselves to the mosquitoes an

发表于:2019-01-08 / 阅读(81) / 评论(0) 分类 Scientific American(一)月

Theres been an unexpected development in our understanding of drug resistance in bacteria. The accepted scenario was a simple case of evolutionary selection. In a bacterial population exposed to a killer drug, a few lucky individuals might have a gen

发表于:2019-01-08 / 阅读(102) / 评论(0) 分类 Scientific American(九)月

Russia has banned the importation of kangaroo meat from Australia. Producers fear the decision will decimate their industry. Russia was the main market for the Australian kangaroo trade, accounting for about 70% of international demand. Russia is wo

发表于:2019-02-12 / 阅读(45) / 评论(0) 分类 VOA标准英语2009年(八月)