office supplies pen pens writing instrument cables demand electricity energy infrastructure pole power supply wires push pins art art brushes art supplies Bristles brush brushes paint painting cast close hub iron open pipe shutoff valve water wheel advice advising alert black communicate communication concern danger electric-power electrical electricity-power-lines equipment height high high-voltage information informing overhead power-lines power-supply protect protection risk risks risky safety sign strength warning wiring yellow metak office pencil point school sharp sharpen sharpener supplies write writing camera dark Expose film light photo photography roll silver artwork background box boxed brown child-creativity children color colored coloring coloring-in colors colour coloured colouring colouring-in colours contained container creativity office-supplies pencils pointed points potential school-supplies sharpened six-pack stationery wood wood-grain wooden writing-implements access-denied access-limitations appropriate-behavior appropriate-behaviour authorise authorised authority building communicating denied electricity-supply exceptions limitations limited limited-entry not-allowed not-permitted prohibited prohibition regulations responsible restricted restrictions warning-sign