In English, vis bears the meaning of "to look at something" and can be combined with affixes to form new words, as in supervise, revise, etc. In this sense, vis is a ______ morpheme.

A．The stories of Harry Potter are criticized in some other cities in U.S except New Mexico.
B．Young people are fascinated with Harry Potter.
C．Christian churches hate Harry Potter.
D．Pastor Jack Brock planned to burn the Harry Potter books on Sunday.

A．before Google, searching online was .impossible
B．before Google, searching online lacked accuracy
C．before Google, searching online was difficult
D．Google is easy to use