下列说法中正确的是( )。
A
暂无解析
ProfessorJohnsonissaid_____somesignificantadvanceinhisresearchinthepastyears.
_________,themostcontroversialcandidateintheelectioncampaign,hehasbeenstronglycriticizedforhiscrudecommentsaboutwomen.
Thecountry’schiefexportsarecoal,carsandcottongoods,cars_____themostimportantofthese.
Modern____perhapscausesmoreproblemsthanitsolves.