Urbanrenewalprogramsstrivetoupgradeareasthatarebecomingslums.

In1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.

Formerly,intheUnitedStates,manynursesworkedasprivatedutynursesratherthaninhospitals.

Someanimalspantandsweattospeedevaporationofbodymoistureandthuscoolthemselves.

Somechildrendisplayanunquenchable难以抑制的curiosityabouteverynewthingtheyencounter.