Thefirstpaperwasmadefromthebarkofthemulberrytree.
Someseaurchins海胆havevenomous(toxin)spines
In1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.
Withlasersscientistscanprobemanyphysicalprocesses,suchascombustion,oncebeyondourken.视野
TheSalkvaccineisamajorfactorinthefighttoeradicatepolio.
Alligatorsstillexistinsomeofthedank潮湿swampsandbayous小海湾ofAlabama'scoastalregions.