全球旧事资料 分类
fromwhereyouaresothatthere
wouldbe
olightforthebooktoreflectthe
youcould
otseethebookeve
with
youreyeswideope

Lighttravelssofastthatthetimei
whichittravelsfromthebookyouarereadi
g
toyoureyesissoshortasiftherewere
otimeatallLightreachesusfromthe
moo
whichisabout380000kilometersawayi
o
lyalittlemoretha
aseco
d
40Youca
seethebookbecause_______
Ayoureyesareclosetoit
Byoureyesightca
gettoit
Cithaslightofitsow

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light
41Theu
derli
edword“lumi
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s_______
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light
42________havelightoftheirow

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a
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dtheearth
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a
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43Whichofthefollowi
gistrue
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gsyouca
seegiveofflight
BLightfromthebookismuchshortertha
thatfromthemoo

CLighttravelssofastthatthereis
otimeforyoutoread
DThemome
tyouope
youreyesthelightfromthebooktravelstoyoureyes
C
Forthousa
dsofyearswehavelookedforwaytomeasuretimeEarlyhuma
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theearththemoo
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ga
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wereusedto
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ight
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The
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theskyTimecouldbetoldmoreaccuratelybysetti
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positio
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ofthis“su
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tohours
Butthesu
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Todayeve
moreaccurateclocksarei
usesuchasbatteryoperatedquartz
clocksdigitalclocksa
dclocksru
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i
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Theseatomicclocksarethemostaccurateclockseveri
ve
tedTheexacttimeca

bekepttowithi
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eseco
dace
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44Whe
somethi
gisveryexactitissaidtobe__________
Aslow
Baccurate
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si
theolddaysused__________totelldayfrom
ight
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Ddigitalclocks
46Asu
dialworksby__________
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