It was not until 1911, _______ the first vitamin was identified, _______ people realized the importance of it．
#85155
A
when; which
B
when; that
C
that; which
D
that; that
推荐题目
How time flies! It's in two months ________ we'll say goodbye to our high school life.
#84704
A
before
B
that
C
until
D
when
Sometimes I wonder ______ that has made me feel differently from the others.
#85192
A
how is it
B
what is it
C
how it is
D
what it is
Is it he or you ________ in charge of the job and supposed to complete it on time?.
#84858
A
who is
B
that is
C
who are
D
whom are
Could it be in the restaurant in ________ you had dinner with me yesterday ________ you left behind your keys and wallet?
#84880
A
which; which
B
which; that
C
that; where
D
where; that