1. Which of the following sources is the main contributor to smog formation in Toronto?

	A. Coal-fired power generation plants
	B. Residential heating systems
	C. Motor vehicles
	D. Industrial manufacturers

2. Ontario's Nanticoke coal-fired electricity generating station produces as much air pollution as:

	A. 35 cars
	B. 3,500 cars
	C. 350,000 cars
	D. 3.5 million cars

3. Sulphur dioxide is a major component of smog and facilitates production of sulphate particulate matter in the air. Which of the following is the leading source of sulphur dioxide (SO2) emissions in Ontario?

	A. Smelters for metal processing
	B. Motor vehicles
	C. Coal-fired generating stations
	D. None of the above