Gurugram, Dec. 7 -- With the air quality index (AQI) at 328, the city's air quality entered the 'very poor' category on Thursday, as per the Central Pollution Control Board (CPCB) bulletin. The last time Gurugram air was in this category was 18 days back on November 16, when the city's AQI's was 360. Since then, the city had been experiencing relatively clean air, thanks to sporadic rain and high wind-speeds....