Backpacks are convenient. They can hold your books,your lunch,and achange of clothes,leaving your hands free to do other things.Someday,if youdont mind carrying a heavy load,your backpacks might also power your MP31player,keep your cell phone running,and maybe even light your wayhome. The backpacks electricity-creating powers depend onsprings used to hang a cloth pack from its metal frame.The frame sits againstthe wearers back,and the whole pack moves up and down as the person walks.Agear mechanism converts vertical movements of the pack to rotary motions of anelectrical generator,producing up to 7.4 watts. The backpack could be especially useful forsoldiers,scientists,mountaineers,and emergency workers who typically carryheavy backpacks.For the rest of us,power-generating backpacks could make itpossible to walk,play video games,watch TV,and listen to music,all at the sametime.Electricity-generating packs arent on the market yet,but if you do get one eventually,just make sure to look both ways before crossing thestreet! 1. Backpacks are convenient because B they can hold as many things as you want to carry. D you do not have to carry things withyou.
各类睡眠问题,怎样用英语做表达
美文故事:一个人的旅行
我淘气的弟弟
聪明的“黑子”
现代人的新毛病:时间饥荒
这样表达你的“愤怒”更酷炫
“heel”的习惯用语,heel不只是你的脚跟
三个近十年内才开始使用的习惯用语,你会用吗?
它就是腐国人民最讨厌的家务活!
假期安全如何保证? 上
“再见”的各种说法,你了解多少
矛盾修辞,让你的口语生动又形象
回忆陪伴过我们的学习用具
不止汉语有叠词,英语叠词也很有趣
呆头呆脑的“blank”短语盘点
教你如何用英语更高大上地哭“穷”
盘点那些让人又爱又恨的室友们
英语单词“get”的用法,你真的get了吗?
关于“钱”的有趣习惯用语
这些意思一般般的习惯用语,你了解多少
“电动滑板”隐藏了很大的安全隐患
英国人最讨厌的十项家务活盘点
人类对地球照成的影响
“某人疯了”的花式表达,你知道多少
什么是“爱的帐篷”?为何突然出现在中国大学里
这三种很讨人厌的人,用英语怎么说
写给朱莉的一封信
职校成立新专业“电子竞技”
FOR SONG 是什么意思?便宜货?
中国家长热衷给孩子报精英教育班
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |