Solidgeometryhasenabledastronomerstocalculatethepositionsoftheheavenlybodiesrelativetooneanother.
In1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.
Somechildrendisplayanunquenchable难以抑制的curiosityabouteverynewthingtheyencounter.
Incalculatingthedailycalorierequirementsforanindividual,variationsinbodysize,physicalactivity,andageshouldbetakenintoaccount.
ThefirstimportantexpositionintheUnitedStateswasheldinPhiladelphiain1876.