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
Mr Smith has_______ cancer for two years but he is still working very hard.
#71387
A
suffered
B
suffered from
C
suffered by
D
suffering from
--Why did the police ______________the crowd?---Because the president’s car __________in the street.
#73149
A
break down; broke down
B
break up; broke up
C
break down; broke up
D
break up; broke down