_______environmental damage is done, it takes many years for the ecosystem to recover.
#31390
A
Even if
B
If only
C
While
D
Once
推荐题目
. Both look very strong and fast,_____ one runner speeds ahead and wins the race.
#80451
A
Therefore
B
And
C
But
D
While
An completely new district of industry has appeared in ________ used to be wasteland.
#30108
A
which
B
that
C
what
D
where
Perhaps the day will come ____ people will be able to breathe clean air in cities．
#32785
A
when
B
while
C
as
D
since