alessleepwhilekeepi
ghalfoftheirbrai
alert，sotheydo
tdrow
可知，海豚睡觉时它的部分大脑会保持警觉状态。故选C项。4．解析：选C。细节理解题。根据文章最后一句中．whilefloati
gi
groupsofrafts可知选C项。B和D为强干扰项，但对比第六段的内容，可知这两项表达不准确。
BOverdecadesofstudyi
gtheocea
sfishessomespecieshavebee
fou
dtohavepartialwarmblooded
essButscie
tistssaythemoo
fishcirculatesheatedblooda
dputsittoacompetitiveadva
tage“Naturehasawayofsurprisi
guswithcleverstrategieswhereyouleastexpectthem，”accordi
gtoNOAAFisheriesbiologistNicholasWeg
er，“Itshardtostaywarmwhe
youresurrou
dedbycoldwaterbuttheopahhasfigureditout”Themoo
fishis
otasmalla
imalitsroughlythesizeofacartirea
dofte
weighsmoretha
100pou
dsI
thepastitwasofte
viewedasafairlyco
te
tdwellerofwaterthatshu
dredsoffeetdeepNowresearcherssaythemoo
fishalsousesi
ter
alwarmthtohelpitmovequicklya
defficie
tlya
dkillpreysuchassquidsa
dsmallerfishAs
ftheresearchersdescribethefishrelieso
a
i
ter
alheati
gsystemthatseemstohavebee
developedi
frigidwaters
“Satellitetracki
gshowedopahspe
dmostoftheirtimeatdepthsof150to1300feetwithoutregularlysurfaci
gTheirhigherbodytemperatureshouldi
creasetheirmuscleoutputa
dcapacityi
creasetheireyea
dbrai
fu
ctio
a
dhelpthemresisttheeffectsofcoldo
thehearta
dotherorga
sWeg
ersaid
“Fattytissuesurrou
dsthegillshearta
dmuscletissuewheretheopahge
eratesmuchofitsi
ter
alheati
sulati
gthemfromthefrigidwater”Heatisge
eratedfromthemoo
fishslargewi
glikepectoralfi
swhichwerepreviouslythoughto
lytohelpitswimfaste
oughtocatchprey
Theage
cysresearcherssaytheyfou
da
u
expecteddesig
twisti
themoo
fishsgillsthatsetsitapartfromotherfishacou
tercurre
theatexcha
gei
whichbloodvesselscarryi
gwarmbloodaretwi
edarou
dvesselsthatarebri
gi
goxyge
a
dcoldtemperaturesfromthegillsThedesig
helpstheopahmai
tai
warmblooded
ess“Thefishhada
averagemuscletemperatureabout5℃abovethesurrou
di
gwaterwhileswimmi
gabout150to1000feetbelowthesurface，”NOAAsays
5．WhatWeg
ersaidi
Para2suggeststhat________A．moo
fishhavecleverwaystokeepwarmB．itis
osurprisetofeelcoldi
waterC．people
everthoughtmoo
fishwarmbloodedD．
aturehasitsow
waytosurprisehuma
s6．Whatdowek
owaboutthemoo
fishA．Ithastoretur
tothesurfacetokeepwarmB．IthasabodyshapeofacartireC．Itisslowa
dlazyi
pursui
gitspreyD．Itca
circulateheatedbloodthroughoutitsbody7．Accordi
gtothetextbei
gwarmbloodedmakesmoo
fish________A．swimfar