If you keep ______ ,you’ll be a very good swimmer one day.

_______ review of 44 studies, American researchers found thatmen and women who ate six key foods daily cut the risk of __________ heart diseaseby 76%

She kept practicing ________ she could win the National Speaking Competition.

下列各句句式特点与其它三项不同的一项是（ ）

Some scientists believe that is no doubt a cure for AIDS will be found