英语四级 阅读

Part IV Reading Comprehension (Reading in Depth) (25 minutes)　　Section A　　 When we think of green buildings, we tend to think of new ones – the kind of high-tech, solar-paneled masterpieces that make the covers of architecture magazines. But the U.S. has more than 100 million existing homes, and it would be __47__ wasteful to tear them all down and __48__ them with greener versions. An enormous amount of energy and resources went into the construction of those houses. And it would take an aver