According to the passage, iron was NOT used for beams, columns, and girders prior to the early eighteenth century because _____.
Đáp án D
the use of charcoal for refining ore produced poor quality iron
Thông tin nằm ở đoạn 1: “…instead of charcoal for refining iron ore. Previously the poor quality of the iron had restricted its use in architecture…”
Theo đoạn văn, sắt đã không được sử dụng cho xà, cột và dầm trước khi đến đầu thế kỷ 18 bởi việc sử dụng than củi để luyện quặng tạo ra sắt chất lượng kém.
Silent reading, especially in public places, flourished mainly because of ___.
Paragraph 4 of the passage serves mainly to do which of the following?
According to the passage, many people’s understanding of desertification is incorrect because _____.
It can be inferred that the emergence of the mass media and specialised reading materials was an indication of ___.
Large amounts of gases may be released from the Sun at the end of its life as a .
The word “degradation” in paragraph 4 is closet in meaning to _____.