首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Complete the table below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer. Talking about the history of bikes
Complete the table below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer. Talking about the history of bikes
admin
2017-02-25
61
问题
Complete the table below.
Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.
Talking about the history of bikes
Good afternoon, ladies and gentlemen. I’d like to take this opportunity to welcome you to our exhibition, "Two Centuries of the Bike". Let’s stroll around the exhibition, shall we?
Although there were a few early efforts back in the 1700s, you didn’t really see many bikes till, say, the 1830s in England. Bikes were a response to the rapid growth of cities early in the 19th Century. Cities like London were getting too big to walk across! The early bike let people travel with less effort than walking. Plus a bike was a lot cheaper than a horse!
Think of it. No one invented a bike for, what, five thousand years of human history? Why did people do it then? Probably because this was the start of the Machine Age: people wanted machines to do all the work.
There were some drawbacks however. For one thing, there were no pedals. You simply pushed yourself along using your feet. Kind of like today’s skateboard. That meant you went fairly slow. And uphill, you actually worked harder, pushing that two-wheeler. Plus, the wheels were made of wood covered with metal, as you can see from this model. So the downside was that the ride was quite uncomfortable on most roads. Only a few gadget lovers had or used them.
By the 1860s, though, improvements were being made. As you can see from this specimen, metal frames had become the rule. They’re more durable than wood, and they don’t warp in the rain. The biggest improvement however was the development of the chain and sprocket system. They are connected. This meant you did not push the bike. You used pedals just like today. You had to try harder to balance, so it took some practice to figure out how to use the pedals. But it made the ride so much easier. As a result, the good thing was that you could ride a lot more smoothly and with very little effort.
By the 1880s, another big change was the use of rubber wheels. These became pretty common at that time. Though the first ones were solid rubber, the ride was a good deal more comfortable than the old iron and wood system. This is a big consideration because the faster you go, the more you feel every bump. Air-filled tyres - "pneumatic tyres" - didn’t really come into use till around the year 1900, as you can see from this exhibition over here. That made the ride even more comfortable.
So, by 1890 or so, people were going a lot faster and a lot more smoothly. There was one problem when you were going quickly and comfortably: "OH NO! HOW DO I STOP"?! Yes, we all laugh now. But for a long time, the only way to stop was drag your feet. That didn’t work very well and it would be dangerous if you were going fast. In the crowded cities of those years -New York, Chicago, and so on - you would get killed if you couldn’t stop for, say, a streetcar.
Plus look at this bike. The front wheel is nearly a meter and two-thirds tall! They made them that way so you could see over people and wagons. But, you couldn’t drag your feet. This model is called a "velocipede" - a "speed pedal." Another characteristic of the bike in this period is that it has two equal-sized wheels, which signaled a big change in bikes.
For with the velocipede, brakes appeared. If you wanted to stop, you just pushed the pedal backwards. Doing that stopped the back wheel of the bike. This technique worked a lot better than dragging your feet, or jumping off the high seat there! This meant that bikes became a great deal safer. It would have been safer if people wore helmets, but the first bicycle helmet wasn’t invented until years later, and even then it was little more than a leather ballcap. It really wasn’t until the 1970s that the bike helmet was modified to provide some real protection.
Before continuing on to look at developments since the 1890s, let’s say a word more about safety. Everyone knows if you’re going downhill, you can get going dangerously fast. To go more than a hundred kilometres an hour isn’t all that difficult! But even on level ground it’s easy to go too quickly. On a city street, today’s bicycles can be ridden at a speed of over forty miles an hour, over a short distance. That’s about sixty-four kilometres an hour. Remember you’re on a bike, not in a car. There’s nothing to protect you. People are killed in single-bicycle accidents every day, just from hitting the road.
A good rule to remember is, if you’re going faster than the cars, slow down. And please wear a helmet. Nearly one-quarter of the epilepsy cases come from head injuries in accidents on bikes and motorcycles. I didn’t mean to scare you, but safety is everyone’s business.
What? Now that’s a good question. Why are today’s bikes so much faster? Well it’s not just that today’s athletes are faster. The answer is partly mechanical. If you look closely here, at the back wheel you’ll see a number of gears. Changing gears is what makes those fast speeds possible. You can shift gears depending on the terrain and how hard you wish to pedal. So you can put it on a higher gear for downhill, and a lower gear for uphill travel to make it easier to climb that slope. You’ll notice this gear-shifting mechanism is attached at the back wheel, and when the rider shifts on the handlebar gear-shifter, the chain moves to the appropriate sprocket. And, speaking of changing gears, let’s look over here at our "Tour de France" exhibit……
选项
答案
connected
解析
connected通过预判词性,可知此题答案需填写形容词或动词的被动形式。在…the chain and sprocket system之后紧接着有一句:They are connected.此处的they即指代前一句中的chain and sprocket(齿轮)。
转载请注明原文地址:https://kaotiyun.com/show/un8O777K
本试题收录于:
雅思听力题库雅思(IELTS)分类
0
雅思听力
雅思(IELTS)
相关试题推荐
Manyproblemsinschoolsarearousedbytheattitudesofstudents.Howdotheseproblemsform?Whatshouldwedotochan
Wildanimalshavenoplaceinthe21stcentury,andtheprotectionisawasteofresource.Towhatextentdoyouagreeordisagr
ThediagramsbelowshowthedevelopmentofthevillageofKelsbeyin1780,1860and2000.Summarisetheinformationbyselec
Somepeopleprefertoplanactivitiesfortheirfreetimeverycarefully.Otherschoosenottomakeanyplansatallfortheirf
Whatdoyouimaginearetheadvantagesanddisadvantagesofworkingabroad,asfarasindividualsandcountriesareconcerned?
Thepositionofwomeninsocietyhaschangedmarkedlyinthelasttwentyyears.Manyoftheproblemsyoungpeoplenowexperience
Somepeoplethinkthatgoodhealthisimportanttoeveryone,somedicalservicesshouldnotberunbyprofit-makingcompanies.D
ThegraphbelowshowstheunemploymentlevelsinIrelandandthenumberofpeopleleavingthecountrybetween1988and2008.Sum
Therearemorenewtownsnowadays.Itismoreimportanttoincludepublicparksandsportsfacilitiesthanshoppingcentresfor
Describethetrendinthechartbelow.ThegraphshowsthepercentageoftheUKadolescentsfollowingvegetariandiet.
随机试题
下列与我国税务有关的说法,不正确的是:
碘酸钾-碘化钾氧化法测定羧酸时,每一个羧基能产生()碘分子。
提出“师范学校立,而群学之基悉定”的教育家是_______。
A公司于2007年1月1日取得B公司10%的股权,成本为500万元,取得投资时,B公司可辨认净资产公允价值总额为4900万元(假定公允价值与账面价值相同)。因对被投单位不具有重大影响,且无法可靠确定该项投资的公允价值,A公司对其采用成本法核算。A公司按照净
既可补肾助阳又能润肠通便的是
男,33岁。近5年来反复出现上腹部疼痛,尤以饱食后明显。今日出现右上腹剧痛,5小时后来院就诊。检查:生命体征平稳,腹部平坦,全腹压痛及反跳痛,腹肌紧张呈板状腹,移动性浊音可疑。此患者首先应该做的检查是
根管机械预备的目的如下,除外
甲喜新厌旧,欲杀害妻子乙后与情妇结婚,虽然明知其儿子丙有与乙在同一饭碗里吃饭的习惯,由于杀乙心切而不顾丙的死活,仍在乙的饭碗里投放毒药。结果乙、丙均中毒身亡。本案中甲对丙死亡的心理态度是()(2011年一专一第3题)
A、Hiscriminalrecord.B、ThehighunemploymentrateinNewYork.C、ThelongdistancebetweenhishometownandNewYork.D、Hisu
A、Hisbitterexperienceabroad.B、WhathesawintheAsiancountries.C、Made-upstoriesbasedonhisimagination.D、Thestories
最新回复
(
0
)