Formulatedin1823,theMonroeDoctrineassertedthattheAmericaswerenolongeropentoEuropeancolonization.
A、emphaticallystatedEyespots,themostrudimentaryeyes,arefoundinprotozoan原生动物flagellates鞭毛虫,flatworms扁形虫,andsegmentedworms片段蠕虫.
Batsfly,ratherthanglide,andthusaretheonlymammalscapableoftrueflight.
Somecosmeticsmanufacturersattempttocapturetherose'sunmistakablefragrance香味insoapsandperfumes.
Someseaurchins海胆havevenomous(toxin)spines
Peoplewhodonotsleepenoughtendtobecomeirritable.
