doubtfuladj.可疑的;怀疑的;不确定的
doubtful about/of对 ... 怀疑
doubtful sponsor list可疑保证人名单
doubtful about result怀疑这个结果
doubtful as to sth.对某事有怀疑
doubtful bill receivable[经] 应收未决票据
doubtful debts provision预提坏账准备
doubtful positive sample可疑阳性样品
"the dubiousness of his claim"
"there is no question about the validity of the enterprise"