At times the balance in nature is ______ , resulting in a number of possibly unforeseen effects. 
#84042
A
troubled
B
confused
C
disturbed
D
puzzled
推荐题目
— What’s up?— There are so many problems ______.
#65457
A
remained to be solved
B
remaining to solve
C
remained solving
D
remaining to be solved
. He was late for the meeting because the bus he took ______ halfway. 
#76946
A
broke in
B
broke down
C
broke out
D
broke up
When they went to the theatre, the play ______ for five minutes.
#76269
A
had begun
B
has begun
C
had been on
D
was on
Having behaved himself so well in prison, he was ___ in the end.
#80732
A
set up
B
set free
C
set out
D
set off