单选题
What draws my firm's attention is the design of cities. When we designed America' s first "green" office building two decades ago, we felt very【C1】______ . But today, the idea that buildings can be good for people and the environment will be increasingly influential in years to come. Back in 1984 we discovered that most manufactured products for decoration weren' t designed for【C2】______ uses. The "energy-efficient" buildings constructed after the 1970s energy crisis revealed indoor air quality problems caused by materials such as paints and carpet. So, we've been focusing on these materials【C3】______ to the molecules, looking for ways to make them safe for people and the planet. Home builders can now use materials that don't【C4】______ the quality of the air, water, or soil.【C5】______ our basic design strategy is focused not simply on being "less bad" ,but on creating completely healthful materials that can be either safely returned to the soil【C6】______ reused by industry again. In fact, the world' s largest manufacturer has already【C7】______ a fully and safely recyclable carpet. No one【C8】______ to create a building that destroys the planet. But our current industrial systems are inevitably causing these conditions. So【C9】______ simply trying to reduce the damage, we are adopting a positive approach. We' re giving people healthful products and an opportunity to make choices that have a【C10】______ effect on the world. It's not just the building industry. Entire cities are taking these environmentally positive approaches to desian. olannina and buildina.