In the experiment we kept a watchful eye ________ the developments and recorded every detail. 
#28560
A
in
B
at
C
for
D
on
推荐题目
I've got all her records but I've never seen her_______. 
#29033
A
in the mood
B
in the flesh
C
in the movement
D
in the nature
The price in different countries will be based________and local economic conditions.
#25850
A
in advance
B
in conclusion
C
on demand
D
at all costs
I’d rather the money went to a _______cause.
#29139
A
valuable
B
rare
C
worthwhile
D
useful