word關於「doubtfully opposite word」標籤，搜尋引擎有相關的訊息討論：
143 Synonyms and Antonyms of DOUBTFUL - Merriam-WebsterSynonyms for DOUBTFUL: distrustful, dubious, hinky, mistrustful, skeptical, ... The words dubious and doubtful are synonyms, but do differ in nuance.缺少字詞： gl= | 必須包含以下字詞：gl=141 Synonyms and Antonyms of DUBIOUS - Merriam-We