According the passage, double-paned windows______________.

35/50

are energy efficient.

should only be used as replacement windows

should only be used in new additions to homes

will lower your heating costs by 50%.

Giải thích

Đáp án A

Thông tin trong bài: "Windows provide another opportunity to cut your energy costs. Caulk old windows that might be leaky to prevent drafts, and choose double-paned windows if you're building an addition or replacing old windows."