Pictured is a street network. All streets are two$-$way, and the dots represent parking meters. $1.$Draw a graph useful for finding an efficient route for checking the meters. How many vertices does it have? $2.$ How many edges are there on the graph that's useful for finding an efficient route for checking the meters? $3.$ Draw a graph useful for routing a garbage truck, assuming the garbage truck needs to drive down a street only once to collect the garbage. How many vertices does it have? $4.$How many edges are there on the graph that's useful for routing a garbage truck? $5.$What is the total valence of the graph that's useful for routing a garbage truck? $6.$Draw a graph useful for routing a street sweeper, assuming the street sweeper needs to drive down a street twice to completely sweep it$.$How many vertices does it have? $7.$How many edges does the graph useful for routing a street sweeper have? $8.$Which of the graphs have an Euler circuit? Check all that apply: the one useful for finding an efficient route for checking the meters; the one useful for routing a garbage truck; the one useful for routing a street sweeper