Helium is a very light gas.氦是一种非常轻的气体。Helium is a gas used in balloons.氦是一种用于气球的气体.Unlike helium - 4, it cannot be produced by radioactive decay.与氦 - 4不同之处是, 氦-3不能由放射性衰变产生....
预防脑炎的草药在这一地区俯拾皆是.Herbs for the prevention of encephalitis can be found everywhere in this area.目的探讨病毒性脑炎的早期临床诊断和治疗.Objective To investigate the early diagnosis and treatment of viral encephalitis.目的根据临床病例分析并总结感染后脑炎的临床特征....