Howwouldyouliketosleepwithonehalfyourbrainasleepandtheotherhalfawake?Dolphinssleepthisway.RecentlyscientistsatIndianaStateUniversityhavediscoveredthatduckssleepthiswaytoo.Theyfoundthatduckssleephalfaw
Howwouldyouliketosleepwithonehalfyourbrainasleepandtheotherhalfawake?Dolphinssleepthisway.RecentlyscientistsatIndianaStateUniversityhavediscoveredthatduckssleepthiswaytoo.Theyfoundthatduckssleephalfawakesotheycanrestandwatchfordangeratthesametime.
Afterputtingtheirducksinarowandvideotapingthemsomeresearchersfoundducksontheendofeachrowspentmoretimeasleepwithoneeyeopenapparentlylookingforpredators.
“Themoretheducksfeltthreatenedthemoretheysleptwithoneeyeopen”saidleadauthorNielsC．RattenborgagraduatestudentatIndianaStateUniversityTerreHaute.”theuniqueaspectisnotthattheydoitbutthattheycontrolit.Whentheysleepattheedgeofagrouptheytendtorealizegreaterdangersotheyspendmoretimesleepingwithonehalfoftheirbrain.”DuckswithoneeyeopenwerestillawakeenoughtodetectpredatorssaidtheauthorsofthestudywhichappearstodayintheJournalNature.
Theresearchersstudiedfourgroupsoffourducksheldinplasticboxeswhichwerearrangedinarow.Ducksontheendwerefoundtosleepwithoneeyeopen31.8percentofthetimecomparedto12.4percentofthetimeforducksinthecentralposition.
Alsoducksinthecentralpositiondidnotopenoneeyemorethantheotherswhileducksoneachendkepttheeyefacingawayfromthegroupopen86.2percentofthetime.Brainwavereadingsoftheducksshowedthatthehalfofthebrainreceivingsignalsfromtheclosedeyeindicatedthathalfofthebrainwassleeping.Signalsfromthehalfofthebrainreceivingsignalsfromtheopeneyeshowedastatebetweenfullyawakeandasleep.
1．Apredatorismostlikelytobe .
A．ascientistwhodoesresearchworkonanimals
B．ahumanbeingwholooksafterandfeedsducks
C．ananimalthathuntskillsandeatsotheranimals
D．ananimalthatislikelytobefriendswithducks
2．Ducksattheendofeachrowsleepwithoneeyeopenbecause .
A．theyarelookingforfood
B．theywanttoenjoythescenery
C．theyarewatchingoutfordanger
D．theyareuniqueintheirsleepinghabit
3．Howmanyduckswereusedintheexperiment?
A．Four. B．Eight.