—Why does the lake smell terrible?—Because large quantities of water .
#103559
A
have polluted
B
is being polluted
C
has been polluted
D
have been polluted
推荐题目
It i s the second time that the poor area_______.
#101272
A
had been visited
B
has been visited
C
was visited
D
is visited
The 2012 London Olympic Games _________ to attract several billion TV viewers around the globe.
#102831
A
is expected
B
will be expected
C
are expected
D
has been expected
Professor Liu has ________ teach psychology since he came to the Central China Normal University.
#104447
A
determination to
B
been determined to
C
been determining to
D
determined to
—Have you known Dr. Jackson for a long time?—Yes, since she _________ the Chinese Society.
#104589
A
has joined
B
joins
C
had joined
D
joined