u
tofelectricalsti
ulatio
requiredtoexciteelectroreceptorsr
ETheamou
tof
ervousactivitytra
smittedtothebrai
byelectroreceptorswhe
theyareextitedr
8Whichofthefollowi
gca
bei
ferredabouttheexperime
tdescribedi
thefirstparagraphr
　AResearchershaddifficultyverifyi
gtheexiste
ceofelectroreceptorsi
thea
teaterbecauseelectroreceptorsrespo
dtosucha
arrowra
geofelectricalfieldstre
gthsr
BResearchersfou
dthatthelevelof
ervousactivityi
thea
teatersbrai
i
creaseddramaticallyasthestre
gthoftheelectricalstimuluswasi
creasedr
CResearchersfou
dthatsomeareasofthea
teaterss
outwere
otse
sitivetoaweakelectricalstimulusr
DResearchersfou
dthatthea
teaterstactilereceptorsweremoreeasilyexeitedbyastro
gelectricalstimulustha
weretheelectroreceptorsr
EResearcherstestedsmallareasofthea
teaterss
outi
ordertoe
surethato
lyelectroreceptorswererespo
di
gtothestimulusr
9Theauthorofthepassagemostprobablydiscussesthefu
ctio
oftactilereceptorsli
es711i
ordertor
Aelimi
atea
alter
ativeexpla
atio
ofa
teatersrespo
setoelectricalstimulir
Bhighlightatypeofse
soryorga
thathasafu
ctio
ide
ticaltothatofelectroreceptorsr
Cpoi
toutaseriouscomplicatio
i
theresearcho
electroreceptorsi
a
teatersr
Dsuggestthattactilereceptorsassistelectroreceptorsi
thedetectio
ofelectricalsig
alsr
Ei
troduceafactorthatwas
otaddressedi
theresearcho
electroreceptorsi
a
teatersr
10Whichofthefollowi
gca
bei
ferredabouta
teatersfromthebehavioralexperime
tme
tio
edi
theseco
dparagraphr
ATheyu
abletodisti
guishbetwee
stimulidetectedbytheirelectroreceptorsa
dstimulidetectedbytheirtactilereceptorsr
BTheyu
abletodisti
guishbetwee
theelectricalsig
alsema
ati
gfromtermitemou
dsa
dthoseema
ati
gfroma
t
estsr
CTheyca
betrai
edtorecog
izeco
siste
tlytheprese
ceofaparticularstimulusr
DTheyreactmorereadilytostro
gtha
toweakstimulir
ETheyaremoreefficie
tatdetecti
gstimulii
aco
trollede
viro
me
ttha
i
a
aturale
viro
me
tr
11Thepassagesuggeststhattheresearchersme
tio
edi
theseco
dparagraphwhoobserveda
teatersbreaki
toa
estofa
tswouldmostlikelyagreewithwhichofthefollowi
gstateme
tsr
ATheeve
ttheyobservedprovidesco
clusiveevide
cethata
teatersusetheirelectroreceptorstolocateu
see
preyr
BTheeve
ttheyobservedwasatypicala
dmay
otreflecttheusualhu
ti
gpracticesofa
teatersr
CItislikelythatthea
teaterslocatedthea
ts
esti
gchamoerswithouttheassista
ceofelectroreceptorsr
DA
teaterspossessaverysimplese
sorysystemforusei
locati
gpreyr
EThespeedwithwhichthea
teaterslocatedtheirpreyisgreatertha
whatmightbeexpectedo
thr