-Why does the Lake smell terrible? -Because large quantities of water       .  
#104968
A
have polluted
B
is being polluted
C
has been polluted
D
have been polluted
推荐题目
I’m calling about the apartment you        the other day. Could you tell me more about it?
#99375
A
will advertise
B
had advertised
C
are advertising
D
advertised
In such dry weather, the flowers will have to be watered if they ____________
#104811
A
have survived
B
are to survive
C
would survive
D
will survive
We_______on this project for four hours. Let’s have a rest.
#103758
A
are working
B
have been working
C
worked
D
had worked
I know little about the accident because not much_________ about it up to now
#99272
A
has said
B
has been said
C
had said
D
had been said