If the machine makes a mistake -- ____ rarely happens -- it gives a warning in the form of a red light.
#77412
A
that
B
which
C
as
D
what
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I' ll never forget Mr. Smith, help we had made great progress.
#77393
A
with his
B
with whose
C
his
D
who
He wrote a long letter ___he explained what had happened in the accident.
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A
what
B
which
C
where
D
how
When television was first introduced, the extent _______ it would affect society could not have been foreseen.
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A
of which
B
of what
C
to which
D
in which