Our Amazing Hands The hand is where the mind meets the world.We use our hands to build fires，to fly airplanes，and to write.The human brain，with its open-ended creativity，may be the thing that makes the human race unique.But without hands，all the ideas we think up would come to nothing.
（1）FFStudy it carefully，you will find something interesting.The thumb alone is controlled by nine separate muscles.The wrist is a group of bones and muscles connected with nerves.The nerves send branches into each fingertip，which makes the fingers extremely flexible. （2）GG
Early hands seemed more unusual and interesting than any hand today.Some animals had seven fingers．Others had eight．But by the time vertebrates （脊椎動(dòng)物） appeared 340 million years ago，the hand had developed to only five fingers.（3）CC
Nevertheless，there are still many different types of hands in living animals.After years of research，scientists are beginning to understand the molecular （分子的） changes in hands．（4）BBThis makes the hands of different animals very similar.There is a network of many genes that builds a hand，and all hands are built on that network.
The discovery has given scientists a deeper understanding of the development of hands.A bird' s wing and a lion's paw （爪） may appear to have nothing in common．（5）EEIt may just be a little more of one protein here，a little less of another there.In the past，scientists could recognize only the outward signs that hands had developed from a common ancestor.Today scientists are uncovering the inward signs as well.
A.Hands can often be used for a number of different purposes.
B.They also see that all hands start out in much the same way.
C.It has kept that number for reasons scientists don't yet know.
D.No one would doubt that the five fingers are different with each other.
E.But the difference between them may come down to a tiny change in form.
F.The reason we can use our hands for so many things is their special structure.
G.So you can see a skilled watchmaker use his hands to set springs in place under a microscope.
【考點(diǎn)】自然科學(xué)研究成果．
【答案】F；G；C；B；E
【解答】
【點(diǎn)評(píng)】
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發(fā)布：2024/5/27 14:0:0組卷：8引用：1難度：0.5
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1．Like a tired marriage，the relationship between libraries and publishers has long been dull.E-books，however，are causing heartache.Libraries know they need digital services，but many publishers are too cautious about piracy and lost sales to co-operate.Among the big six publishers，only Random House and Harper Collins license e-books with most libraries.
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So publishers keep adjusting their lending arrangements in search of the right balance.Random House raised its licensing price earlier this year，and Harper Collins limits libraries to lending its titles 26 times.The story of the library e-book is a nail-biter.
（1）It can be inferred from Paragraph 1 that.
A．several big publishers have sold e-books to libraries
B．both libraries and publishers caution the e-book piracy
C．some publishers are hesitant to cooperate with libraries
D．libraries are eager to keep strong relationship with publishers
（2）What worries publishers about people's switch to e-books？
A．The risk of e-book piracy.
B．The possible decline of book sales.
C．No time limit for the downloaded book files.
D．The availability of the incompatible e-book formats.
（3）We can learn from Paragraph 3 and 4 that.
A．Amazon is adopting measures to win more customers
B．OverDrive distributes e-books and audio files to publishers
C．over half of Americans are borrowing e-books from libraries
D．the fees of lending e-books are under the control of publishers
（4）What is the best title for the text？
A．The Hopeful Future of Publishing Business
B．The Uncertain Economics of Lending E-books
C．The Dull Relationship between Libraries and Publishers
D．The Close Cooperation between OverDrive and Amazon發(fā)布：2025/1/1 16:0:1組卷：1引用：3難度：0.5 -
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A.It's the same with social media.
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G.For example，just because higher social media use co-occurs with higher levels of depression doesn't mean social media use causes depression.發(fā)布：2025/1/1 15:0:2組卷：6引用：3難度：0.5
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