In 1900, the energy derived from burning petroleum was only four percent ______ of coal.

Thosewhochangemobilephonestoofrequentlywillhavetopayforbeing______.

Americans eat ______ vegetables per person today as they did in 1910.

OneoftheresponsibilitiesoftheCoastGuardistomakesurethatallships______followtrafficrulesinbusyharbors.

I was shocked by the number of people who seemed to have nothing better to do with their timethan ______ to know fish better.