短语词组短语doubtful of about 怀疑doubtful view about ancient history 疑古史观be doubtful about 对;疑惑的remaining doubtful about sth 半信半疑地were doubtful about 从第三段意思可知“因为她是一个对农业没有任何经验的大学生I am doubtful about that 我对此表示怀疑 返回 doubtful about