【根据短文内容，回答下列问题。I’llNeverForgetThatDayWhenIwas8yearsoldmyfathertookmybrotherandmeonapicnic.OnthatdayIdidsomethingwrongandIwillneverforg】

　　 根据短文内容，回答下列问题。

　　                I’llNeverForgetThatDay 

　　 WhenIwas8yearsoldmyfathertookmybrotherandmeonapicnic.OnthatdayIdidsomethingwrongandIwillneverforgetit.

　　 Itwasasunnyday;Iwasveryhappyandexcited.Whenwearrivedtheremyfatherwarnedmethattheriverwasverydangerousandmademepromisenottowalkuptoit.IpromisedmyfatherbutIdidnotkeepmypromise.

　　 IforgetwhyIwalkedintotheriver.MaybeIwascurious.IwalkedintotheriverandIfelldownbecausetheriverwasverydeep.Icouldnotstandortouchthebottom.Icriedoutloudlybutnobodywasthereexceptmyyoungerbrother.

　　 Irememberthatmyyoungerbrotherwasveryscaredanddidnotknowwhathecoulddobecausehewasjustoneyearyoungerthanme.Hejumpedintotheriverbutthatjustmadethesituationworsebecausehewasevenshorterthanmeandhecouldnotswim.Bothofuscriedout.

　　 Fortunatelytherewasafarmerwhowasworkingthere.Hefoundusandsavedmefirst.AtthattimeIcouldnolongerseemybrother.IcriedlouderandIshoutedtothefarmer“Pleasesavemybrother!”Hewasveryshockedbecauseitturnedouthehadonlyseenme.Heaskedme“Areyousurethatyourbrotherfellintotheriver?”“OfcourseIamsure!”Ianswered. 

　　 Thenmyfatherarrivedandstartedlookingformybrotherintheriver.Finallytheyfoundhimandtookhimtothehospital.LuckilymyyoungerbrotherwasaliveorelseIcouldneverforgivemyself.

　　1.Howmanypeoplewerethereonthepicnic?

　　2.Whydidthefatherwarnthewriternottowalkuptotheriver?

　　3.Howoldwasthewriter'sbrotherwhenhewantedtosavethewriter?

　　4.Whosavedthewriteratlast?