The part of the environmental movement that draws my firm's attention is the design of cit

ies, buildings and products. When we designed America's first so-called“green” office building in New York two decades【C1】______, we felt very alone. But today, thousands of people come to green building conferences, and the【C2】______that buildings can be good for people and the environment will be increasingly influential in years to【C3】______

Back in 1984 we discovered that most manufactured products for decoration weren't designed for【C4】______use. The“energy- efficient”sealed commercial buildings constructed after the 1970s energy crisis【C5】______indoor air quality problems caused by materials such as paint, wall covering and carpet. So for 20 years, we've been focusing on these materials【C6】______to the molecules, looking for ways to make them【C7】______for people and the planet.

Home builders can now use materials- such as paints that release significantly【C8】______amounts of organic compounds-that don't【C9】______the quality of the air, water, or soil. Ultimately,【C10】______, our basic design strategy is focused not simply on being “less bad” but on creating【C11】______healthful materials that can be either safely returned to the soil【C12】______reused by industry again and again. As a matter of【C13】______, the world's largest carpet manufacturer has already【C14】______a carpet that is fully and safely recyclable(可循环利用).

Look at it this way: No one【C15】______out to create a building that destroys the planet. But our current industrial systems are【C16】______causing these conditions, whether we like it or not. So【C17】______of simply trying to reduce the damage, we are【C18】______a positive approach. We're giving people high-quality, healthful products and an opportunity to make choices that have a【C19】______effect on the world.

It's not just the building industry, either.【C20】______cities are taking these environmentally positive approaches to design, planning and building. Portland, Seattle and Boston have said they want to be green cities. Chicago wants to be the greenest city in the world.

【C1】

A．off

B．away

C．before

D．ago