英文时态问题,我的动词的时态对吗,不对的请指出啊.
Alifeboatsetouttonighttosearchfortheshipwreck.thecrewsentradiomesagestothewreckuntiltheyreceivedasignalfromthemenonboard.assoonastheyrecieveasignal,theytryandfindthewreckwithpowerfulsearchlights.themomentthecrewlocatethewreck,theyfireaspecialgunwhichcarryaropefromthelifeboattothesinkingship.iftheseaisrough,theywillpouroilonthewater.theyaresuretosucceed,butiftheyfail,ahelicopterwillbesentouttomorrowmorning.helicoptersareveryusefulforrescuework,buttheycannotbeusedatnight.