With the fast development of puter and Internet technologies, traditional printed books ______ by the growing popularity of online reading of e-books.A.are challengedB.have challengedC.are being challengedD.have been challenged
网友回答
C解析考察时态和语态。根据句意可知本题应该使用被动语态，排除B项。根据句意可知传统的印刷书本正受到电子书的挑战。