单词：multiple speed
单词：multiple speed 相关文章
This is Scientific American's 60-Second Science. I'm Karen Hopkin, this'll just take a minute. On February 8th, we told you about scientists who had created a device worn over the knees that could harvest the energy you otherwise waste while walking.
Scientific American(二)月
One main goal in the renewable energy field is to find an efficient, inexpensive way to split water into hydrogen and oxygen. The hydrogen could then be used as a fuel source for vehicles or fuel cells. Typically, an electric current breaks the water
60秒科学
One main goal in the renewable energy field is to find an efficient, inexpensive way to split water into hydrogen and oxygen. The hydrogen could then be used as a fuel source for vehicles or fuel cells. Typically, an electric current breaks the water
Scientific American(四)月
Sunscreen comes in many forms, each with its own impacts on your body and the environment. 防晒霜有很多种，每种对你的身体和环境影响各有不同。 With so many options, how do you choose which sunscreen is best for you? 有了这么
TED演讲教育篇
Offering Substitute 提供代用品 Specimen Letters1. Offering Rayon in Place of Watered Silk提供人造丝代替水洗丝Dear Sirs,Thank you for your fax of yesterday (April 3) with your order No.456 for 5,000 metres of 100cm wide watered silk. We
实用英语
By Jessica Berman Washington 13 February 2008 Scientists in the United States say they have developed fabrics that can generate electricity. Researchers say they have harvested enough electricity to power small electronic devices such as an mp3 playe
VOA常速英语2008年（二月）