英 [ˈdaʊtf(ə)l] 美 [ˈdaʊtf(ə)l]
adj. 怀疑的，不确定的；未必的，不大可能的；不可靠的
doubtful /ˈdaʊtfʊl/ CET4 TEM4
形容词 If it is doubtful that something will happen, it seems unlikely to happen or you are uncertain whether it will happen. 不大可能的
For a time it seemed doubtful that he would move at all.
短期内他似乎不大可能搬走。
形容词 If you are doubtful about something, you feel unsure or uncertain about it. 不能肯定的
I was still very doubtful about the chances for success.
我仍然不能肯定成功的可能性有多大。
副词 不能肯定地
Keeton shook his head doubtfully.
基顿将信将疑地摇了摇头。
形容词 If you say that something is of doubtful quality or value, you mean that it is of low quality or value. 有问题的
...selling something that is overpriced or of doubtful quality.
…销售价格过高或质量有问题的东西。
形容词 If a sports player is doubtful for a match or event, he or she seems unlikely to play, usually because of injury. 不太可能的
Forsyth is doubtful for tonight's game with a badly bruised leg.
福赛斯因为严重的腿伤不太可能参加今晚的比赛。
有疑问的-引用次数：2
参考来源挪用公款罪法益新论
该词在阅读理解题中出现频率也很高，是表示语气的常用词：doubtful（怀疑的），sympathetic（赞成的），critical（批评的），objective（客观的）。
1907年，AMA把当时160所医学院分成可接受（Acceptable）、可疑的（Doubtful）、不可接受（Unacceptable）三类。
... doubt n.疑惑；疑问；怀疑 doubtful adj.怀疑的，可疑的；难以预测的，未定的 dove n.鸽子 ...
... positively adv. 绝对地，完全地 doubt; doubtful; uncertain; dubious 表示不是很肯定 I bet 我肯定 ...
可疑的；令人生疑的；疑心的；不能确定的
We were doubtful about the practicability of the plan.
我们怀疑这个计划是否切实可行。
This wine is of doubtful quality.
这酒的质量有问题。
Rose was doubtful about the whole idea.
罗斯对整个设想持怀疑态度。
But some are doubtful the reforms will work. Boston University School of Law professor Cornelius Hurley.
VOA : standard.2010.03.16
State Department Spokesman P.J.Crowley said the United States welcomes the visit by President Lula, but that it is doubtful it will yield anything useful.
VOA : standard.2010.05.14
She took a doubtful step and then undid it To raise herself and look again.
她犹豫地踏出了一步又收了回来,又上去继续往下看。
现代诗歌课程节选 : 耶鲁公开课
However spokesman Crowley said interaction between Clinton and her Iranian counterpart in Kabul is doubtful.
VOA : standard.2010.07.16
It is doubtful that they will put much pressure on companies to boost returns.
Although the IRS commissioner has denied any staff acted out of partisan motives, political critics are doubtful.
Compromise is a doubtful way to fix a limit, though a common one among politicians.