TOEFL Listening: ETS-TOEFL听力机经 - 9RZ3C339FLR11ANMP$

According to the Professor, why did art historians' working before the nineteen century find it challenging to analyze early Netherlandish painting? A. The paintings were not usually signed. B. There were few written sources describing the methods of Netherlandish painters. C. Many of the painting had been damaged over time. D. Many painters imitated the works of other painters. E. Art historians disagreed about the definition of early Netherlandish painting.