Someseaurchins海胆havevenomous(toxin)spines
A、sensuous(feeling)Solidgeometryhasenabledastronomerstocalculatethepositionsoftheheavenlybodiesrelativetooneanother.
The Salk vaccine is a major factor in the fight to eradicate polio.
Cream of tartar 酒石 , a weak acid, can be added to egg whites to help them foam泡沫 when they are beaten
ThefirstimportantexpositionintheUnitedStateswasheldinPhiladelphiain1876.
The Native American interpreter Sacajawea was a valuable member of the Lewis and dark expedition in 1805.
