Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered...

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 18 to 22.

        Cities often feel noticeably hotter than the surrounding countryside, a phenomenon known as  the urban heat island (UHI). An urban heat island is a metropolitan area that becomes significantly warmer than nearby rural regions, largely because concrete, asphalt, and buildings absorb and retain heat. In such  environments, waste heat, generated by cars, public transport, factories, homes, and even people  themselves, (18) ____________. When buildings and paved surfaces are constructed close together, they trap  heat, and this insulation effect, which slows the release of warmth, causes temperatures in the spaces between structures to remain high even after sunset.

        At night, the contrast becomes especially clear. Surfaces such as roads, sidewalks, and parking lots  act like vast reservoirs of heat, preventing warmth from escaping into the cooler night sky. In a dense city core, skyscrapers and narrow streets restrict airflow, (19) ____________. The consequences are serious: poorer  air quality develops because pollutants released by vehicles and industry cannot disperse easily, while  local water systems are harmed when heated runoff enters streams and rivers, damaging aquatic species  adapted to cooler conditions. Urban heat islands also place a heavy strain on energy networks, since  residents increasingly rely on air conditioning during summer peaks, (20) ____________.

        To reduce these effects, urban planners, policymakers, and architects are developing both modest  and ambitious strategies. Green roofs, essentially gardens on rooftops, help cool buildings by absorbing sunlight and converting it into biomass rather than heat. (21) ____________. Expanding urban vegetation and  creating more open layouts improves air circulation, allowing heat to dissipate. Though urban heat islands represent a modern challenge, thoughtful design and collective action can lessen their impact, (22) ____________.

(Adapted from https://education.nationalgeographic.org)

Question 18. 

        A. in addition to the rising temperatures                 B. adds to the rising temperatures

        C. which adds to the rising temperatures                 D. with addition of the rising temperatures