Despite the proliferation of other faster modes of transportation, the railroads remain the largest carriers of intercity freight in the United States.
A、schemesB
暂无解析
Someseaurchins海胆havevenomous(toxin)spines
Eyespots,themostrudimentaryeyes,arefoundinprotozoan原生动物flagellates鞭毛虫,flatworms扁形虫,andsegmentedworms片段蠕虫.
Formerly,intheUnitedStates,manynursesworkedasprivatedutynursesratherthaninhospitals.
Withtheacquisitionofsmallercompaniesbylargerones,the1960'ssawawaveofnewconglomerates.
Insectpestsareamongtheleadingcausesofcropfailure.
