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【简答题】
由40% 的聚酰胺 -6 和 60% 的聚酰胺— 6 , 6 组成的聚合物混合体 ( 初级形状 )
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皮皮学刷刷变学霸
举一反三
【单选题】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
【单选题】Do you know that the first textbooks written for teaching English as a foreign language ____ in the 16th century?
A.
came up
B.
came along
C.
came out
D.
came about
【单选题】The first textbooks _____ for teaching English as a foreign language came out in the 16th century.
A.
being heard
B.
to be written
C.
being written
D.
written
【单选题】The first textbooks written for teaching English as a foreign language _____ in the 16th century. [ ]
A.
came about
B.
came out
C.
came along
D.
came up
【单选题】The first textbooks for teaching English as a foreign1anguage came out in the 16th centry ．
A.
． have written
B.
． to be written
C.
． being written
D.
． written
【单选题】The first textbooks ______ for teaching English as a foreign language came out in the 16th century.
A.
to be written
B.
written
C.
being written
D.
having written
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