7.Although the causes of cancer ____， we do not yet have any practical way to prevent it.
#105343
A
are being uncovered
B
have been uncovering
C
are uncovering
D
have uncovered
推荐题目
My money ________.I must go to the bank to draw some of my savings outbefore I've none in hand.
#105320
A
has run out
B
is running out
C
has been run out
D
is being run out
—What's that noise?—Oh，I forgot to tell you.The new machine ________.
#105313
A
was tested
B
will be tested
C
is being tested
D
has been tested
Today many physical bookstores ________ down with financial difficulties, inflexible management strategies and competitive pressure from online bookstores.
#105310
A
had closed
B
having closed
C
being closed
D
are closing
In China, farmers are ______ from the central government’s new policies on agriculture.
#105328
A
suffering
B
profiting
C
earning
D
learning