Although the causes of cancer ________, we do not yet have any practical way to prevent it．

Although the causes of cancer ________, we do not yet have any practical way to prevent it．

#103264

have uncovered

have been uncovering

are uncovering

are being uncovered

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We are a little worried because we _____ the ground as a leader in the field of IT with the others speeding up development．

#103205

are losing

were losing

lost

have lost

 The prices are _____ fast these days. Nobody can get the prices _____.

#104710

going down; to bring down

rising; to be bringing down

raising; bring down

going up; brought down

Prince William said he was delighted that the 2012 Olympic Games ________ in London.

#103400

would be held

would hold

will be held

will hold

—Beg your pardon, but I didn’t quite catch what you said.—Oh, I         to myself.

#101947

have talked

am talking

had talked

was talking

I’m afraid I won’t be available then. I _____ a friend off at 3:00 this afternoon.

#100822

see

am seeing

will see

will be seeing

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