_____ a certain doubt among the workers as to whether he could finish the task in a short time．
#34562
A
It was
B
There had
C
There existed
D
It had
推荐题目
He knew that cholera would never be controlled _____ its cause was found.
#32471
A
till
B
still
C
until
D
kill
Whatever is left over may be put into the refrigerator，________ it will keep for two or three weeks.(2011·安徽)
#30498
A
when
B
which
C
where
D
while
Many workers were organized to clear away remained of the World Trade Center.
#30115
A
those
B
that
C
what
D
where
I thought her to be nice and honest ________ we met.
#29965
A
first time
B
for the first time
C
the first time
D
for the last time
We should consider the professor’s advice _______ our school library provide more books on popular science.
#34143
A
that
B
when
C
which
D
where