15．It's a scene in many homes around the world:tired-eyed teens wake to the sound of their alarm clo——青夏教育精英家教网—

15．It's a scene in many homes around the world：tired-eyed teens wake to the sound of their alarm clock．Another school day begins，and we all wish we could have just one extra hour of sleep．
For lucky high school students in England，they're now going to reset their alarm and get an extra hour of sleep．Instead of starting school at 9am，students will begin the academic day at 10am．
This is part of a huge study by Oxford University．The experiment will see whether later classes can improve exam results．
More than 100schools across England will join the four-year experiment，which includes tens of thousands of students．It is based on scientific evidence that teenagers are out of step with traditional school hours．
"We know that something funny happens when you're a teenager，"lead sleep researcher Colin Epsie told The Telegraph．"Your parents think it's because you're lazy and everything would be OK if you could get to sleep earlier．But science is telling us that teenagers need to sleep more in the mornings．"
A similar experiment in 2009saw an improvement of 19percent in exam scores for major subjects-such as math and science．
Teenagers'sleep cycles，on average，begin two hours after adults．Neuroscientists say teens have a built-in clock，which makes them more likely to go to sleep around midnight．As well as not feeling fully awake until between 9am and 10am．This body clock stays until the age of 19for females and 21for males．
Schools are places for learning，as well as education laboratories--finding out the best ways to learn and increase knowledge．Yet we'll have to wait until 2018to find out these exciting results!
38．England high school students usually start schoolD．
A．at 7am
B．at 8am
C．at 9am
D．at 10am
39．Teenagers struggle to get up early becauseD．
A．they are too lazy to get up early
B．their body clock won't start to work until 9am
C．they stay up studying late at night
D．their sleep cycles are later than adults
40．The aim of the experiment in 2009was toA．
A．find out if later classes can improve exam results
B．test how students'body clocks work
C．compare teenagers'and adults'sleeping patterns
D．help teachers to find the best way to teach
41．The article is focused on the topic thatB．
A．teenagers need more sleep than adults
B．students might need more hours'sleep in the morning
C．boys need more sleep in the morning than girls
D．it is important to do more experiments on education．

14．Since 1850，the temperature of Earth's surface has increased about 0.6℃．Scientists predict（预测） it may warm much more by the end of this century．Who's turning up the heat？Well，it seems that we are!Some of this global warming may be natural．However，nearly all scientists now agree that most of it is due to people's actions．Over the past 150years，we've give out large amounts of gases，
especially carbon dioxide （CO2）to the air． These gases can keep heat near Earth's surface，so more carbon dioxide means more heat is kept near Earth's surface．Global warming may change the weather in ways that lead to more severe（严重的） storms，floods and droughts．
We add carbon dioxide to the air when we burn things，especially fossil fuels（矿物燃料）．Fossil fuels are energy sources formed from the remains of plants and animals that lived millions of years ago．Coal，oil，and natural gas are all fossil fuels．People in the United States and other countries started burning large amounts of fossil fuels more than a century ago．The amount of fossil fuels being burned each year has been increasing worldwide．The more we burn，．
What can we do to help？Nowadays to live a low-carbon life is quite popular in the world．Low-carbon means to reduce the amount of carbon dioxide．Saving energy and reusing are the key words．In fact，even the simplest everyday activities can make our lives low-carbon．
66．What problem can global warming cause？（根据课文内容回答问题）Global warming may change the weather in ways that lead to more severe storm，floods and droughts．
67．What are fossil fuels？（同上）Fossil fuels are energy sources formed from the remains of plants and animals that lived millions of years ago．Coal，oil，and natural gas are all fossil fuels．
68．请将第一段中的划线句子翻译成汉语．在过去的150年间，我们向空气中排放了大量这类气体，特别是二氧化碳．
69．请根据第二段内容，将最后一个句子补充完整．the more carbon dioxide will be produced．
70．请写出日常生活中的一种"低碳"行为（用英语写一个句子）．We'd better go to school by bike or on foot．．

13．With a determined （坚定的） look on his face，Chicago's Michael McCarthy held on to the banister （扶手） and climbed to the top of the Willis Tower．The great Tower stands 1，451feet （442meters） tall，the （15）Bbuilding in the US．As he got to the last step，McCarthy （16）D fell down，but that didn't stop him．The 14-year-old boy finally finished climbing the 2，109steps and arrived at the top，where he （17）Acheers from many people．
"I just want to show people that （18）Ca kid with no legs can do it，anyone can do it，"McCarthy said．
McCarthy，who was born without legs，has to wear prosthetic legs （假肢） and use a stick to walk．But McCarthy has a strong （19）A．He believes that having a disability shouldn't stop anyone achieving his or her success．
He has been in a special school since he was four．When he decided to climb the Willis Tower，his teacher，Jeff Kohn，was （20）C by his determination （决心） and offered to help train him．They spent more than ten hours practicing climbing stairs and keeping balance with the prosthetics and sticks on the steps every day．"It seems that he never knows how difficult it is．Sometimes I was so tired that I asked him to rest for a day，"said Kohn．"But he said he was still full of energy and wanted more （21）D．"
Kohn always walked with McCarthy for the climb．"I （22）Bthe last 10floors，he went faster，"said Kohn．
"He's the least craven（懦弱的） sportsman I've ever trained"．
McCarthy said he was （23）Dof himself and that the tower now holds special meaning．"When I'm older，I'll （24）A to the building and say'Look at this building I climbed，"he said．

15．A largest	B highest	C earliest	D latest
16．A seldom	B hardly	C always	D almost
17．A enjoyed	B needed	C made	D kept
18．A while	B after	C if	D though
19．A heart	B hope	C body	D love
20．A pleased	B beaten	C moved	D asked
21．A friends	B helpers	C time	D exercise
22．A tried	B saw	C did	D met
23．A thinking	B talking	C worried	D proud
24．A point	B go	C turn	D hurry