(as) firm as a rock坚如磐石

(as) light as a feather轻如鸿毛

(as) close as anoyster守口如瓶

(as) mute as a fish噤若寒蝉

(as) strong as a horse强壮如牛

(as) cool as a cucumber泰然自若

(as) sober as a judge十分清醒

(as) sure as a gun千真万确