sceptical adj.
VERBS be, look, remain | become
ADV. deeply, extremely, highly, very | increasingly | fairly, mildly, rather, slightly, somewhat in a mildly sceptical tone of voice | openly They remained openly sceptical about her promises of improvement.
PREP. about He is deeply sceptical about the value of teaching poetry. | as to Many were sceptical as to whether the plan would succeed. | of They are highly sceptical of political leaders.
You can also check other dicts: sceptical (English, 中文解释 ), wordnet sense, Collins Definition