TOEFL Listening: TPO-TOEFL阅读TPO - V5XSHR4N21I84U1ON$

Paragraph 4 supports the idea that a city's heat-island intensity would increase if A. the city went into an economic decline and lost population B. the city's economy shifted from heavy industry to health care and education C. there was an upward trend in the average age of the city's residents D. repair work on the streets slowed traffic throughout the city