TheSalkvaccineisamajorfactorinthefighttoeradicatepolio.
A、completelydestroyAnoversight遗漏(miss,overslaugh)inproofreadingoftenresultsinprintederrors.
Foodmustbemoistinordertohaveataste.
Urbanrenewalprogramsstrivetoupgradeareasthatarebecomingslums.
Formerly,intheUnitedStates,manynursesworkedasprivatedutynursesratherthaninhospitals.
Someseaurchins海胆havevenomous(toxin)spines