有关X线对比度指数特点的叙述，正确的是
A、管电压升高，对比度指数上升C
暂无解析
翻译：IbelieveChineseeconomicauthoritiesrecognizetheproblemandthenextFive-YearPlanwilladdressiteffectively.
Ittookafewsecondsforhereyesto________tothedarkness.
―________finedayitistoday!
ThechildhoodofTomSawyerandHuckFinnintheMississippiisarecordofavanishedwayoflifeinthe()Mississippivalley
OxfordAdvancedLearnersDictionary’,3rdEdition(1980),isamongthebest-knownBritish______dictionaries.
