In1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.
A、strangeDoubleEagleinthefirsttransatlanticballoon,wasgreetedbyavidcrowdsinFrance.
Withlasersscientistscanprobemanyphysicalprocesses,suchascombustion,oncebeyondourken.视野
Communicationisoneofthemostimportantbondsthatholdculturalsystemstogether.
Thefirstpaperwasmadefromthebarkofthemulberrytree.
Formerly,intheUnitedStates,manynursesworkedasprivatedutynursesratherthaninhospitals.
