Haveyoueverwonderedwhybirdssing?Maybeyouthoughtthattheywerejusthappy.Afterallyouprobablysingwhenyouarehappy.Somescientistsbelievethatbirdsdosingsomeofthetimejustbecausetheyarehappy.Howevertheysing

Haveyoueverwonderedwhybirdssing?Maybeyouthoughtthattheywerejusthappy.Afterallyouprobablysingwhenyouarehappy.

Somescientistsbelievethatbirdsdosingsomeofthetimejustbecausetheyarehappy.Howevertheysingmostofthetimeforaverydifferentreason.Theirsingingisactuallyawarning(警告)tootherbirdstostayoutoftheirterritory.

Doyouknowwhata“territory”is?Aterritoryisanareathatananimalusuallythemaleclaims(声称)asitsown.Onlyheandhisfamilyarewelcomethere.Nootherfamiliesofthesamespeciesarewelcome.Yourhouseisyourterritorywhereonlyyourfamilyandfriendsarewelcome.Ifastrangershouldenteryourterritoryandthreatenyouyoumightshout.Probablythiswouldbeenoughtofrightenhimaway.

Ifsoyouhaveactuallyfrightenedthestrangerawaywithouthavingtofighthim.Abirddoesthesamething.Butheexpectsanoutsideralmostanytimeespeciallyatnesting(筑巢)season.Soheisscreaming(尖叫)allthetimewhetherhecanseeanoutsiderornot.Thisscreamingiswhatwecallabird’ssonganditisusuallyenoughtokeepanoutsideraway.

Birdssingloudestinthespringwhentheyaretryingtoattractamateandwarnothersnottoentertheterritoryoftheirs.

Youcanseethatbirdshavealanguagealltheirown.Mostofithastodowithattractingmatesandsettingupterritories.

1．Somescientistsbelievethatmostofthetimebird’ssingingisactually________.

A．anexpressionofhappiness B．awayofwarning

C．anexpressionofanger D．awayofgreeting

2．Whatisabird’s“territory”?

A．Aplacewherefamiliesofotherspeciesarenotaccepted.

B．Aplacewhereabirdmayshoutatthetopofitsvoice.

C．Anareaforwhichbirdsfightagainsteachother.

D．Anareawhichabirdconsiderstobeitsown.

3．Whydobirdskeeponsingingatnestingseason?

A．Becausetheywanttoinvitemorefriends.

B．Becausetheirsinginghelpsfrightenoutsidersaway.

C．Becausetheywanttofindoutsidersaround.

D．Becausetheirsinginghelpsgetridoftheirfears.

4．Howdoesthewriterexplainbirds’singing?

A．Bycomparingbi