1 .

2 .

4 . Researchers have found that urban heat island effect made worse by sunbaked roads can be relieved by a simple measure: Paint the streets gray.

A study by Arizona State University found that _________a reflective, gray-colored material to black asphalt（柏油）resulted in a 10.5-to-12-degree Fahrenheit drop in average road surface temperatures. Meanwhile, sunrise temperatures _________an average 2.4-degree drop.

“This is exactly what we were hoping for,” Phoenix Mayor Kate Gallego said. “It’s exciting to see a technology that has the potential to meet the demands of a growing desert city in a world where temperatures are_________rising.”

Experts say road temperatures in the Phoenix area can rise to 180 degrees on a hot day. That_________energy remains in paved surfaces for hours, radiating heat back into nighttime air. Higher overnight temperatures result in warmer mornings, creating a_________of urban heat island effect.

Researchers found as well that the greatest temperature_________was near the road surface, with less dramatic results 6 feet above the ground. Even so, the neighborhoods with streets reflecting light experienced air temperatures 0.3-to-0.5 degree cooler compared with neighborhoods with_________roads.

But reflective pavements don’t affect all surfaces the same way. Researchers said that “the most meaningful measurement” was of radiant temperatures, a measure of how the body_________heat. Those measurements showed that the “human experience of heat_________at noon and the afternoon hours was higher due to surface reflectivity.” It’s been noted that the increase in__________ temperatures “may be a necessary trade-off（妥协）to reduce surface temperatures using a reflective surface.”

Heather Murphy, a spokesperson for the Transportation Department, said the response has been __________from drivers and residents in neighborhoods where the material is applied. “We have had some people who don’t like the look of it, but generally the response has been very__________”.

Still, officials cautioned that reflective pavement is not a remedy for the urban heat island effect.

“If you’re standing over these surfaces on a hot day,__________, you’re still going to be hot if you’re not in the shade,” said Jennifer Vanos, an assistant professor at Arizona State University. “So if we really want to __________true solutions, it’s not going to be just painting all the streets gray.”

A second phase of the study will examine questions about how the material performs under different__________, including changes in reflectivity, degradation and subsurface temperature over longer periods.