According to paragraph 1, the environmental goals...

Câu hỏi: According to paragraph 1, the environmental goals set by green builders were initially considered unrealistic presumably because......................

A. there was an abundance of natural materials for the construction of conventional buildings.

B. there was a lack of green builders at the beginning of the 20th century.

C. the problems of environment destruction were not prevalent at the time.

D. the potential applications of technology to constructing green buildings were not recognised then.