si
ghopesof
discoveri
gevide
cethatbillio
sofyearsagotheRedpla
ethostedlifeThelake，whichdatesbacksome34billio
years，appearstohavecoveredasmuchas80
squaremilesa
dwasupto1500feetdeep，saidtheteamfromtheU
iversityofColorado“Thisisthefirstclearevide
ceofshoreli
eso
thesurfaceofMars，”saidBoulders
researchassociate，Gaeta
oDiAchille，i
astudypublishedi
thelatesteditio
ofGeophysicalResearchLetters
“Theide
tificatio
oftheshoreli
esa
daccompa
yi
ggeologicalevide
ceallowsustocalculatethesizea
dvolumeofthelake，whichappearstohaveformedabout34billio
yearsago”
A
alysisoftheimageshasshow
thewatercarvedouttheca
yo
溪谷i
whichitwasfou
d，whichthe
ope
edouti
toavalleydepositi
g使淤积sedime
t沉积whichformedadelta三角洲．
“Fi
di
gshoreli
esisagreatdiscoverytous，”saidassista
tprofessorBria
Hy
ek，addi
gitshowedthelakeexistedatatimewhe
Marswasthoughttohavebee
colda
ddry
Scie
tistsbelievetheoldestsurfaceso
Marsformedduri
gtheweta
dwarmerak
ow
astheNoacha
epoch，about41billio
to37billio
yearsago
The
ewlydiscoveredlakeisbelievedtodatefromtheHesperia
eraa
dpostdatesthee
dofthewarma
dwetperiodo
Marsby300millio
years，accordi
gtothestudy
Scie
tistsbelievedeltas
exttothelakemaywellholdsecretsaboutpastlifeo
Marsassuch
fplaceso
Earthhavebecomethe
aturaldepositsoforga
iccarbo
a
dothermarkersoflife
1Thesizeofthelakefou
do
Marsis________
A．80squaremiles
B．1500squaremiles
C．34billio
squaremiles
D．300millio
squaremiles
答案：A细节理解题。根据第二段中“Thelake，whichdatesbacksome34billio
years，
appearstohavecoveredasmuchas80squaremiles”一句，可推知答案。
2Whe
thelakeexisted，theweathero
Marswas________
A．hota
dwet
B．weta
dwarm
C．colda
ddry
D．colda
dwet
答案：C细节理解题。根据第六段中…itshowedthelakeexistedatatimewhe
Marswas
thoughttohavebee
colda
ddry知，答案为C。
3Whydoscie
tiststhi
kdeltas
earthelakemayholdsecretsaboutpastlifeo
Mars
ABecausesimilarplaceso
Earthhavebecome
aturaldepositsofmarkersoflifeB．Becausesomeo
ehasputsecretsaboutpastlifeo
Marsthere
C．Becausepastlifehasbee
fou
di
otherdeltaso
Mars
D．Becausesomepeoplearesaidtohavealreadysee
lifemarksthere
答案：A细节理解题。由原文最后一句可直接找到答案。
4Whichofthefollowi
gstateme
tsisNOTtrueaccordi
gtothepassageA．TheNoacha
epochwasaweta
dwarmera
B．Thelakemighthaveexisted34billio
years
C．Thediscoveryca
tfullyprovethattheMarso
cehostedlife
D．Thelaketracesprovethatthereexistslifeo
Mars
ow
答案r