The Salk vaccine is a major factor in the fight to eradicate polio.
A、completelydestroyA
暂无解析
Despitetheproliferationofotherfastermodesoftransportation,therailroadsremainthelargestcarriersofintercityfreightintheUnitedStates.
Someseaurchins海胆havevenomous(toxin)spines
EllaGrasso,electedgovernorofConnecticutin1974,supportedtheenactment(given,granted)ofafreedom-of-informationlaw.
Whencarbonisaddedtoironintheproperproportions,theresultissteel.
Eyespots, the most rudimentary eyes, are found in protozoan原生动物 flagellates 鞭毛虫 , flatworms 扁形虫 , and segmented worms片段 蠕虫 .
