For many people who live in cities, parks are an important part of the landscape. They provide a place for people to relax and play sports, as well as a refuge from the often harsh environment of a city. What people often overlook is that parks also provide considerable environmental benefits. One benefit of parks is that plants absorb carbon dioxide - a key pollutant - and emit oxygen, which humans need to breathe. According to one study, an acre of trees can absorb the same amount of carbon dioxide that a typical car emits in 11,000 miles of driving. Parks also make cities cooler. Scientists have long noted what is called the Urban Heat Island Effect: building materials such as metal, concrete, and asphalt absorb much more of the sun's heat and release it much more quickly than organic surfaces like trees and grass. Because city landscapes contain so much of these building materials, cities are usually warmer than surrounding rural areas. Parks and other green spaces help to mitigate the Urban Heat Island Effect. Unfortunately, many cities cannot easily create more parks because most land is already being used for buildings, roads, parking lots, and other essential parts of the urban environment. However, cities could benefit from many of the positive effects of parks by encouraging citizens to create another type of green space: rooftop gardens. While most people would not think of starting a garden on their roof, human beings have been planting gardens on rooftops for thousands of years. Some rooftop gardens are very complex and require complicated engineering, but others are simple container gardens that anyone can create with the investment of a few hundred dollars and a few hours of work. Rooftop gardens provide many of the same benefits as other urban park and garden spaces, but without taking up the much-needed land. Like parks, rooftop gardens help to replace carbon dioxide in the air with nourishing oxygen. They also help to lessen the Urban Heat Island Effect, which can save people money. In the summer, rooftop gardens prevent buildings from absorbing heat from the sun, which can significantly reduce cooling bills. In the winter, gardens help hold in the heat that materials like brick and concrete radiate so quickly, leading to savings on heating bills. Rooftop vegetables and garden herbs can also provide fresh food for city dwellers, saving them money and making their diets healthier. Rooftop gardens are not only something everyone can enjoy, they are also a smart environmental investment. (englishforeveryone.org/PDFs/Level_9_Passage_6) Question 35: According to the passage, the Urban Heat Island Effect is caused by the fact(s) that ______. A. cities are warmer than nearby rural areas B. building materials absorb more of the sun's heat than organic surfaces C. building materials release the sun's heat more quickly than organic surfaces D. city landscapes contain so much of green spaces Question 36: The word “mitigate” in paragraph 2 probably means ______. A. strengthen and intensify B. alleviate or reduce C. destroy or damage D. absorb and consume Question 37: Using the information in paragraph 3 as a guide, it can be inferred that ______. A. cities with rooftop gardens are cooler than those without rooftop gardens B. some plants are not suitable for growth in rooftop gardens C. most people prefer parks to rooftop gardens D. most people prefer life in the country over life in the city Question 38: Which of the following best describes the main difference between parks and rooftop gardens? A. Parks are expensive to create while rooftop gardens are not. B. Parks are public while rooftop gardens are private. C. Parks absorb heat while rooftop gardens do not. D. Parks require much space while rooftop gardens do not. Question 39: The author claims all of the following to be the benefits of rooftop gardens EXCEPT ______. A. increased space for private relaxation B. savings on heating and cooling costs C. better food for city dwellers D. improved air quality Question 40: According to the author, one advantage that rooftop gardens have over parks is that they ______. A. decrease the Urban Heat Island Effect B. do not require the use of valuable urban land C. replenish the air with nourishing oxygen D. are less expensive than traditional park spaces Question 41: The word “their” in the last paragraph refers to ______. A. rooftop vegetables B. garden herbs C. city dwellers D. rooftop gardens Question 42: The author's tone in the passage is best described as ______. A. descriptive B. passionate C. argumentative D. informative