Air quality reports in Dundee make uncomfortable reading. On still winter days, nitrogen dioxide near main roads reaches close to three times the legal limit, and doctors blame the pollution for a long list of chest and breathing problems among children and the elderly. For residents of the flats above the ring road, the difference is not an abstraction but something they breathe. The city's answer is to push electric cars, with new charging points on every residential street and free parking for electric vehicles in the centre. Sales have responded: one new car in five is now electric, up from almost none five years ago. Charging habits, drivers admit, matter too: most vehicles sit idle for twenty hours a day, and the grid must absorb evening peaks when everyone plugs in. Officials have also promised yearly air-quality readings at the same fifty roadside points, so residents can judge for themselves whether the strategy is working. Yet some researchers urge caution. Electric cars clean the air but not the streets: they still cause jams, still need parking space, and their weight wears down tyres and roads. A city full of silent electric cars, they argue, is only half a solution. The first year of readings, planners hint, will decide how quickly the next charging district is approved. Planners are listening. The newest transport plan treats the electric car as one tool among many — better bus lanes, safer cycling routes and cheaper season tickets all appear alongside the charging points. The goal, officials insist, is fewer car journeys in total, not merely cleaner ones. Cleaner exhaust, in other words, is the beginning of the conversation about city transport, not the end of it.
选词填空：Officials have also promised yearly air-quality readings at the same fifty roadside points, so residents can judge for themselves whether the ______ is working.