Formulatedin1823,theMonroeDoctrineassertedthattheAmericaswerenolongeropentoEuropeancolonization.

Someseaurchins海胆havevenomous(toxin)spines

Oneofthegreatestbreakthroughsforprofessionalwomencamein1973whenthefieldofbankingopenedupforthem.

Inliterature,caricatures讽刺画usuallycontainverbalexaggerationthroughwhichthewriterachievescomicandoftensatiric讽刺effects.

Thefearofsmallpox,whichterrorizedtheeighteenthcentury,hasnoanalogy(likeness)today.