With the fast development of computer and Internet technologies, traditional printed books ______ by the growing popularity of online reading of e-books.

A．are challenged

B．have challenged

C．are being challenged

D．have been challenged

室温下，下列各组离子在指定溶液中能大量共存的是 [ ]

A.饱和氯水中 Cl^-、NO₃^-、Na⁺、SO₃^2-

B.c(H⁺)＝1.0×10^-13 mol· L^-1溶液中 C₆H₅O^-、K⁺、SO₄^2-、Br^-

C.Na₂S溶液中 SO₄^2-、K⁺、Cl^-、Cu²⁺

D.pH=12的溶液中 NO₃^-、I^-、Na⁺、Al³⁺