With the fast development of computer and Internet technologies, traditional printed books ______ by the growing popularity of online reading of e-books.
#101859
A
are challenged
B
have challenged
C
are being challenged
D
have been challenged
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When his wife returned from abroad, Kevin ____ his paintings at the art museum in his hometown. 
#100569
A
was exhibiting
B
exhibited
C
would exhibit
D
had been exhibiting
They_____trouble lifting the heavy box.
#103891
A
didn’t have many
B
hadn’t a lot of
C
didn’t have much
D
haven’t a great deal of