Read the passages: Passage A — One way to enjoy a healthier lifestyle is to grow your own vegetables. That way, you know they are free from harmful chemicals. Where do you start if you want to grow your own healthy food? Start with the soil.

If this is your first adventure in gardening, start small. Choose plants that are easy to tend and that will grow well in the soil you have. Deciding what to grow is the first step and it will help decide how big of a garden you want. Not all plants grow in the same way. You have to consider which plants prefer sunlight and which prefer shade. This will help with picking the best spot for your garden.

Once you have decided where you will plant your garden, you can move on to planning your garden's layout. You don't want your tall plants growing next to the shorter ones and blocking out the sun. You also want to make sure there is enough room between the rows to allow for weeding. Proper planning makes planting a breeze.

Passage B — It is more expensive to build a green roof than it is to lay asphalt or shingles on a roof, but the trend is growing. The basic green roof requires a frame, waterproof membrane, gravel for drainage, fibrous material to retain moisture, soil for planting, and a barrier that prevents roots from penetrating the building.

Green roofs started in Europe and are now gaining a strong foothold in the United States. The largest green roof in New York City is built on the roof of a processing and distribution facility. It is actually the biggest green roof in the country. Being in New York, it has faced snow, rain, freezing, and thawing. It has survived it all.

The city of Chicago, Illinois, now has more green roofs than any other U. S. city. There are 7 million square feet of green roofs planted across the city. Toronto, Canada, is the first city in the western hemisphere to mandate green roofs on all new tall buildings. Green roofs are beneficial, not only to the environment, but also to the cities that build them. A recent study in Toronto suggested that if 75 percent of the flat roofs were greened, the city could save $37 million a year on storm water management and energy bills.

Explain why people are building green roofs to live healthier lives. Use information from both texts in your answer.