ElectricBackpack　　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.　　A It produces electricity forelectronic devices while the wearer walks.　　C It is small andconvenient.　　3. The word springs inParagraph 3 means　　B the season of the year，occurring between winter and summer.　　D a length of metal woundaround，which returns to its original shape after　　4. According to Paragraph 4，what does Rome plan to do?　　B To put the backpack on the market.　　D To promote the backpack in anewspaper or on television.　　ways before crossing the street!?　　B Enjoyingelectronic devices while walking may invite traffic accidents.　　D It is wise of you to have such abackpack.　　1.C第一段告訴我們，因為背包可以裝許多東西，所以可以將雙手解放出來做其他事情：tofree your hands to do other things。　　3.D springs在此是彈簧的意思。spring是一個多義詞：泉水、春天、彈跳。　　5.B這個句子的字面意思是：如果你終于得到這樣的背包，過馬路時一定要兩面都看看。也就是說，不要因為同時玩著游戲，聽著音樂、看著電視，太專注以致不注意來往車輛了。

　　ElectricBackpack　　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.　　A It produces electricity forelectronic devices while the wearer walks.　　C It is small andconvenient.　　3. The word springs inParagraph 3 means　　B the season of the year，occurring between winter and summer.　　D a length of metal woundaround，which returns to its original shape after　　4. According to Paragraph 4，what does Rome plan to do?　　B To put the backpack on the market.　　D To promote the backpack in anewspaper or on television.　　ways before crossing the street!?　　B Enjoyingelectronic devices while walking may invite traffic accidents.　　D It is wise of you to have such abackpack.　　1.C第一段告訴我們，因為背包可以裝許多東西，所以可以將雙手解放出來做其他事情：tofree your hands to do other things。　　3.D springs在此是彈簧的意思。spring是一個多義詞：泉水、春天、彈跳。　　5.B這個句子的字面意思是：如果你終于得到這樣的背包，過馬路時一定要兩面都看看。也就是說，不要因為同時玩著游戲，聽著音樂、看著電視，太專注以致不注意來往車輛了。