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
推荐题目
The next day is Thanksgiving Day,a special moment _________ we can express our gratitude, respect and love we feel all year round．
#75776
A
which
B
when
C
where
D
／
I wish to thank Professor Smith, without ______ help I would never have got this far.
#75344
A
who
B
whose
C
whom
D
which
Mr. Obama paid a visit to China in November, 2009, _______, needless to say, must strengthen the Sino-US ties.
#77381
A
what
B
that
C
which
D
it
As a student of Senior Three, he has very little free time __ he can spend developing his own interest.
#78357
A
when
B
in which
C
at which
D
that