beach boat empty lake lonely pond sand sea shadow shore sign signs surf surfer surfing warning water wave windsurfer advice alert appropriate-behavior appropriate-behaviour avoid be-careful black care careful caution communicating communication concern danger dangerous flammable gas gaseous natural-gas no-ignition outlet potential red risk risks risky safety stay-clear vapour vapours warned warning-sign white appropriate behavior appropriate behaviour blue chinese colors colours directions emergencies emergency english languages protect protection rain rain-drops slip slippery slippery floor slippery surface slipping warning sign wet wet surface yellow denied not allowed not permitted permission denied polluted pollution prohibited prohibition rules toxic toxicity water pollution water toxicity weathered worn crossroads junction minor road roadsign roadsigns side side-road sideways announcement beware children informing kids Look looking lookout observant slow slow-down slower watch watch-out bricks death fork omen pitchfork. hay wall access-denied access-limitations authorise authorised authority building electricity electricity-supply exceptions limitations limited limited-entry not-allowed not-permitted power power-supply regulations responsible restricted restrictions traffic vehicles cars monitored monitoring noted observed site-regulations speed