Emergency Care and Transportation of the Sick and Injured ...

1. Even with many more vehicles and many more miles being driven, the number of pollution days has decreased substantially over the years. 2. One of the earliest control devices was the positive crankcase ventilation (PCV) system. a. First used around 1961 and later became mandatory. b. Stops release of hydrocarbons from crankcase of engine. 3. ................
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