题目内容：
根据以下材料，回答题BrightonisapopularseasidetownonthesouthcoastofEngland.Notlongago,somepolicemenwerevery21.Therehadbeenseveralseriousaccidents22bymotoristsdrivingtoofast.Thepolice
startedtosetupaspeedtrap(速度监视器）.Theymeasured23of88yardsonastraightroadandwatchedtosee24acartookto25thatfar.Theyknewthatifaeartooksixmseconds,itwastravelingfaster26the27limitof30milesanhour.
Whenthepolicemenwereready,theyhid28ahedge(树篱)andstartedtotimepassing
cars.Duringtheirfirsthalfanhour,theycaughtfivedrivers.Thepolicemenwrotedownthe29ofeachcarandthenameandaddressofthedriver.Butforthenexthalfanhourthepolicemendidn't
seeanybody30toofast.Theythoughtthatthiswasvery31.Oneofthemdroveaquarterofamilealongtheroadandsawtwostudents32onthegrass,Theywereholdingupasheetofcupboardso
thatmotoristscotddseeit.Onthenoticeoneofthestudents33:"Danger.Speedtrap."
Thepolicementookthenoticeawayandwrotedownthenamesofthestudents.Laterontheywereeachfined5for34tostopthepolicecatchingmotoristswhowere35thelaw.
A．pleased
B．excited
C．delighted
D．puzzled
参考答案：
答案解析：