Eyespots,themostrudimentaryeyes,arefoundinprotozoan原生动物flagellates鞭毛虫,flatworms扁形虫,andsegmentedworms片段蠕虫.
A、hostile-lookingFormerly,intheUnitedStates,manynursesworkedasprivatedutynursesratherthaninhospitals.
Insectpestsareamongtheleadingcausesofcropfailure.
In1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.
Anoversight遗漏(miss,overslaugh)inproofreadingoftenresultsinprintederrors.
InthenortheasternUnitedStates,itrainsintermittently间歇地throughoutthespring.
