Although the principle was known to the Chinese as early as 1000 A. D, it was not until the 13th and 14th centuries in Europe (26) _________ it was put to practical use in the form of eyeglas

13/40

Although the principle was known to the Chinese as early as 1000 A. D, it was not until the 13th and 14th centuries in Europe (26) _________ it was put to practical use in the form of eyeglasses.

when

than

then

that

Giải thích

Đáp án đúng là D

Kiến thức: Cấu trúc “It was not until”

Giải thích: Cấu trúc “It was not until”: It was not until + S + V2/ed + that + ... : mãi cho đến khi

Dịch nghĩa: Mặc dù nguyên lý này đã được người Trung Quốc biết đến từ năm 1000 sau Công nguyên nhưng phải đến thế kỷ 13 và 14 ở châu Âu, nó mới được đưa vào sử dụng thực tế dưới dạng kính đeo mắt.