The first textbooks _______ for teaching English as a foreign language came out in the 16th century.
A. having written B. to be written C. being written D. written
The first textbooks _______ for teaching English as a foreign language came out in the 16th century.
A. having written B. to be written C. being written D. written
D
表示“被动、完成”用过去分词作定语。