handkerchief handsome handwriting handy handle manual chairman statesman politician manner demand permanent forever external exterior superior vary change constant distant instant instance error sponsor outstanding stand understanding standard confidence perform form formation inform formal informal former latter reform platform transform uniform unit unite unity union communicate communication community communism communist unique opportunity value valuable valid valley Silicon Valley硅谷 evaluate vacant vacation vain compass curious occur curtain carpet blank blanket cure secure safe guard accurate accuracy precise precision exercise criticize critical accident incident core record corn score dozen decade according concern care sense nonsense sensitive insensitive sensitivity present presence presently nowadays currently previously represent send senior junior mental sentence fundamental