Solidgeometryhasenabledastronomerstocalculatethepositionsoftheheavenlybodiesrelativetooneanother.
A、ontopofSomeseaurchins海膽havevenomous(toxin)spines
In1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.
Foodmustbemoistinordertohaveataste.
TheSalkvaccineisamajorfactorinthefighttoeradicatepolio.
Alllivingorganisms,regardlessoftheiruniqueidentity,havecertainbiological,chemical,andphysicalcharacteristicsincommon.
