valid: implies being supported by objective truth or generally accepted authority: absence will be excused for ~ reasons.     (supported by符合)   (authority译作准则较好)


sound: implies a basis of flawless reasoning or solid gounds: a ~ proposal for combatting terrorism.


cogent: may stress either weight of sound argument and evidence or lucidity of presentation: the prosecutor's ~ summation won over the jury.     (weight of sound argument and evidence论证有力)  (lucidity of presentation表述清晰)  (summation总结概括)


compelling: suggests a power to overcome doubt, opposition, or reluctance to accept: a documentary that makes a ~ case for court reform.


telling: suggests an immediate and crucial effect striking at the heart of a matter and may or may not imply soundness and validity: a ~ example of bureaucratic mentality.


valid正当合理: 符合客观事实公认准则，sound正确合理: 无瑕的推理，坚实的基础，cogent有力的: 论证有力或表述清晰，compelling让人信服: 能克服疑虑反对犹豫，telling说明问题的: 击中问题核心，直接有力，无论是否合理(may or may not imply soundness, validity)


记忆方法: 1) 首字母记忆VSCCT重组成China VS Chinese Taipei中国对阵中华台北<==合理正当性的竞争

         2) 合理的意思是能让人接受或关注mean having such force as to compel attention or acceptance.