The word “it” in paragraph 2 refers to_____. A. industrial architecture B. internal iron skeleton C. stone D. strength
The word “it” in paragraph 2 refers to_____.
A. industrial architecture
B. internal iron skeleton
C. stone
D. strength
Đáp án B
internal iron skeleton
Thông tin nằm ở đoạn 2: “By 1800 a complete internal iron skeleton for buildings had been developed in industrial architecture replacing traditional timber beams, but it generally remained concealed.”
=> it = internal iron skeleton