In____review of 44 studies, American researchers found that men and women ____who ate six key foods daily cut the risk of ______ heart disease by 76%.
—Lucy doesn't mind lending you her dictionary. —She________. I have borrowed one.
He________have completed his work; otherwise, he wouldn't be enjoying himself by the seaside.
He paid for a seat, when he________have entered free.
________such heavy pollution already, it may now be too late to clean up the river.
John, look at the time,________you play the piano at such a late hour?