stiff: may apply to any degree of this condition: muscles will become ~ if they are not stretched.            (bend使弯曲)


rigid: applies to something so stiff that it can't be bent without breaking: a ~ surfboard.


inflexible: stresses lack of suppleness or pliability: for adequate support, rock-climbers wear shoes with ~ soles. (supple: 物体柔软身体柔韧皮肤弹性supple object,skin,body)


tense: suggests a stretching or straining to the point where elasticity or flexibility is lost: ~ nerves. (elastic: 可拉伸而不断)


wooden: suggests the hard inflexibility and dry rigidity of wood and connotes stiffness and lack of life and often clumsy or heavy deadness: moved in a start ~ manner.


stiff僵硬: 泛指任何程度的难以弯曲，rigid僵硬: 指僵硬到弯曲就会被折断的程度， inflexible不灵活: 指不柔软难拉伸，tense紧张: 表示拉伸或挤压到无法再拉伸挤压的程度，wooden木头般的:  形容像木头般了无生气，感觉僵硬死板笨重


记忆方法: 1) 首字母SIT WR坐着写字<=脖子僵硬

               2) 僵硬 的意思是难以弯曲mean difficult to bend.首字母SIT WR坐着写字<=脖子僵硬    (bend不再直)