1、Thetrafficsignalturnedred,soallthecarsstopped.

2、Sheusedhandsignalstocommunicatewithherfriendwhowasacrosstheroom.

3、Thesmokesignalalertedthenearbyvillagerstothedanger.

4、Thecompanyissuedasignaltoallemployeestoevacuatethebuildingimmediately.

5、Theloudexplosionsignaledthestartoftherace.

6、Hegaveasignalforthemusictobeginplaying.

7、Theweatheralertsignalwarnedresidentsoftheapproachingstorm.

8、Thelighthouseemitsasignaltowarnshipsoftherockycoast.

9、Theteamcaptainusedahandsignaltotellhisplayerstochangetheirstrategy.

10、Theradiosignalwastooweaktoreceiveacleartransmission.

11、Therefereeblewthewhistle,signalingtheendofthegame.

12、Thealarmsignalwokeeveryoneupinthemiddleofthenight.

13、Theconductorgaveasignalfortheorchestratostartplayingthenextmovement.

14、Thebird'schirpingisasignalthatspringhasarrived.

15、Thepilotsignaledthepassengerstoputontheirseatbeltsastheywereabouttoland.

16、Theteacherusedasignaltogetthestudents'attentionbeforestartingherlesson.

17、Thesoldiersignaledtohiscomradestomoveoutofharm'sway.

18、ThesmokesignalwasusedasameansofcommunicationbyNativeAmericans.

19、Thesecurityguardsawsomethingsuspiciousandsignaledforbackup.

20、Thepoliceofficerusedahandsignaltotellthedrivertopullover.

21、Therefereesignaledforapenaltykickaftertheplayercommittedafoul.

22、Thefirealarmsignalpromptedeveryonetoevacuatethebuildingimmediately.

23、Theairtrafficcontroltowersignaledtheplanetocirclearoundandwaitforlandingclearance.

24、Thecoachsignaledforatime-outtodiscussanewstrategywithhisplayers.

25、Theflashinglightonthedashboardsignaledthatthecarneededtobeserviced.

26、Thedrummerusedasignaltocuetherestofthebandtocomein.

27、Theweatherradarsignalshowedastormapproachingthearea.

28、TheTVstationbroadcastasignaltoalltheviewerstotuneinforbreakingnews.

29、Thespeaker'sgesturesignaledthatitwastimeforapplause.

30、Thecellphonesignalwasweakintheremotearea.

31、Thelifeguardsignaledfortheswimmerstoreturntotheshoreasastormwasapproaching.

32、Thetrainconductorusedawhistletosignalthetrain'sdeparture.

33、Theflagmansignaledthestartoftheracebywavingagreenflag.

34、Thebeepingsoundsignaledthatthemicrowavehadfinishedheatingupthefood.

35、Thenavigationsystemlostitssignalintheundergroundparkinggarage.

36、Theartistmadeasignalforthemusictostopplayingwhilesheaddressedthecrowd.

37、Thesirensignalwarnedresidentsoftheapproachingtornado.

38、Theradiosignalwasstrongenoughtoreceiveacleartransmissionfromthespacecraft.

39、Thebird'scallsignaledthearrivalofanewday.

40、Thepoliceofficerusedahandsignaltotellthepedestriantostopcrossingthestreet.

41、Theshipcaptainsignaledtothecrewtoprepareforastorm.

42、Thealarmsignalalertedthesecurityguardtoabreak-inatthemuseum.

43、Thesearchandrescueteamusedasignaltonotifythehelicopteroftheinjuredhiker'slocation.

44、Thecoachsignaledforthequarterbacktothrowalongpassdownthefield.

45、Thecellphonesignalwaslostinthetunnel.

46、Thesmokesignalwasusedasameansofcommunicationduringwars.

47、Theteamcaptainusedahandsignaltotellhisplayerstopickupthepace.

48、Theweatherstationissuedasignalforaseverethunderstormwarning.

49、Theflashingtrafficsignalwarneddriversofthebridgebeingunderconstruction.

50、Thedoorbellsignalsthearrivalofavisitoratyourdoor.