radical

• Radical theories examine history and trace a theory of stages of development .
  激进理论考察历史，并探索一套发展阶段的理论。
• No change in atomic number is possible without a radical change in properties .
  性质不发生根本的改变，原子序数的改变是不可能的。
• The polar concepts of the physical organic chemist are relevant to radical reactions .
  物理有机化学家的极性概念能够适用于基反应。
• Any free radicals in martian soil could be taken as presumptive evidence of life there .
  火星土壤中的任何游离基将可用来推断火星存在生命。
• Both were new and radical experiments, considered by other countries subversive .
  两者都是又新又猛的试验。其他国家都认为他们起的是破坏作用。