For many years, environmental problems have been a major concern to people. Almost all things are related to the word "Green", say, green buildings. A green building means not only the colour of the paint. Also,it refers to environmentally friendly houses,factories and offices. Green building means "reducing the impact  of the building on the land", Taryn Holowka of the US Green Building Council in Washington D.C.said. According to Holowka,buildings account for 65 percent of total US electricity use.  But green buildings can reduce energy and water use. Also,the buildings are often located near public transportation such as buses and subways,so that people can drive their cars less.That could be good for the environment,because cars use lots of gas and give off pollution. Green buildings are often built on developed land,so that the buildings don't destroy forests. Marty Dettling is the project manager for a building that put these ideas into action.The Solaire has been called the country's first green highrise building.  According to Dettling,"We've reduced our energy use by onethird and our water by 50 percent." The Solaire cuts energy in part by using solar power."On the surface of the building we have solar panels which change the sun's energy into electricity,"Dettling explained. The Solaire also has lights that automatically turn off when people leave the room. In addition,the building has lots of windows,allowing people to use the sun for light during the day.The Solaire cuts water by reusing it. Not everyone is eager to move into a green building,however. Some people think that things like solar panels cost more money than more traditional energy source. Anyhow,Holowka said,"It is going to take off." The main idea of the passage may be   _  .    .
settling designed the first green building in the US energy shortage calls for buildings of new design the Solaire serves as a model of high buildings green buildings help save environment
Question: For many years, environmental problems have been a major concern to people. Almost all things are related to the word "Green", say, green buildings. A green building means not only the colour of the paint. Also,it refers to environmentally friendly houses,factories and offices. Green building means "reducing the impact  of the building on the land", Taryn Holowka of the US Green Building Council in Washington D.C.said. According to Holowka,buildings account for 65 percent of total US electricity use.  But green buildings can reduce energy and water use. Also,the buildings are often located near public transportation such as buses and subways,so that people can drive their cars less.That could be good for the environment,because cars use lots of gas and give off pollution. Green buildings are often built on developed land,so that the buildings don't destroy forests. Marty Dettling is the project manager for a building that put these ideas into action.The Solaire has been called the country's first green highrise building.  According to Dettling,"We've reduced our energy use by onethird and our water by 50 percent." The Solaire cuts energy in part by using solar power."On the surface of the building we have solar panels which change the sun's energy into electricity,"Dettling explained. The Solaire also has lights that automatically turn off when people leave the room. In addition,the building has lots of windows,allowing people to use the sun for light during the day.The Solaire cuts water by reusing it. Not everyone is eager to move into a green building,however. Some people think that things like solar panels cost more money than more traditional energy source. Anyhow,Holowka said,"It is going to take off." The main idea of the passage may be   _  .    .
A. settling designed the first green building in the US
B. energy shortage calls for buildings of new design
C. the Solaire serves as a model of high buildings
D. green buildings help save environment
Answer: