"the candidate's doubtful past"
"he has a dubious record indeed"
"what one found uncertain the other found dubious or downright false"
"it was more than dubitable whether the friend was as influential as she thought"
"they were doubtful that the cord would hold"
"it was doubtful whether she would be admitted"
"dubious about agreeing to go"
"drew a few tentative conclusions"
1.未必的;不大可能的
If it isdoubtful that something will happen, it seems unlikely to happen or you are uncertain whether it will happen.
e.g. For a time it seemeddoubtful that he would move at all...
有一段时间他似乎根本不会搬家。
e.g. It isdoubtful whether Tweed, even with his fluent French, passed for one of the locals...
尽管特威德能说一口流利的法语，他是否能被当作当地人还很难说。
2.怀疑的;疑惑的;拿不定主意的
If you aredoubtful about something, you feel unsure or uncertain about it.
e.g. I was still verydoubtful about the chances for success...
我对能否成功仍然深表怀疑。
e.g. Why did he sound sodoubtful?
为什么他听上去如此不确定？
3.(质量或价值)低劣的，不可靠
If you say that something isof doubtful quality or value, you mean that it is of low quality or value.
e.g. ...selling something that is overpriced or ofdoubtful quality...
售卖漫天要价或质量低劣的东西
e.g. They also seemed of verydoubtful value.
它们好像也没有多大价值。
4.(通常指运动员因伤)不大可能参加（比赛）的
If a sports player isdoubtful for a match or event, he or she seems unlikely to play, usually because of injury.
e.g. Forsyth isdoubtful for tonight's game with a badly bruised leg.
福赛斯腿部严重擦伤，不大可能参加今晚的比赛。
1. 可疑的：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. 很多美国医生对AMA日益因循守旧、自私自利的姿态非常不满,他们不但不参加AMA,而且还成立了自己的组织,与AMA针锋相对,反其道而行之.
2. doubtful是什么意思
2. 表示不是很肯定：◆positively adv. 绝对地,完全地 | doubt;doubtful; uncertain; dubious 表示不是很肯定 | ◆disadvantage n. 短处,缺点
3. doubtful什么意思
3. 怀疑的,可疑的：doubt 怀疑,疑问,不相信 |doubtful 怀疑的,可疑的 | doubtless 无疑的,很可能的
这件事的真假是可疑的。
The fact that he won the first place is doubtful.他得了第一名是让人可疑的。
He is an author of doubtful reputation.他是一位名声不太好的作家。
The ethics of his decision are doubtful.他的这一决定是否合乎道德规范值得怀疑。
I am doubtful about the propriety of granting such a request.我怀疑答应这项要求是否合适。
It is doubtful whether the old man will recover from the operation.那老人手术后是否会康复难以确定。
Rose was doubtful about the whole idea.罗斯对整个设想持怀疑态度。
He was doubtful about accepting extra work.他拿不定主意是否接受额外工作。
It's doubtful if this painting is a Picasso.这未必就是毕加索的画。
With her injuries it's doubtful that she'll ever walk again.她多处受伤，今后能否行走还很难说。
It's doubtful whether the car will last another year.这辆汽车未必还能用上一年。
He is injured and is doubtful for the game tomorrow (= unlikely to play) .他受了伤，明天未必能参赛。
At the beginning of the war things were looking very doubtful.战争刚开始时，形势看上去很不明朗。
This wine is of doubtful quality.这酒的质量有问题。
Why did he sound so doubtful?为什么他听上去如此不确定？
...selling something that is overpriced or of doubtful quality...售卖漫天要价或质量低劣的东西
They also seemed of very doubtful value.它们好像也没有多大价值。
Forsyth is doubtful for tonight's game with a badly bruised leg.福赛斯腿部严重擦伤，不大可能参加今晚的比赛。
I was still very doubtful about the chances for success...我对能否成功仍然深表怀疑。
It is doubtful whether Tweed, even with his fluent French, passed for one of the locals...尽管特威德能说一口流利的法语，他是否能被当作当地人还很难说。
For a time it seemed doubtful that he would move at all...有一段时间他似乎根本不会搬家。
I am very doubtful of that.我很疑心那件事.
It is doubtful whether he can read my fortune or not.他能否算出我的运气还是个疑问.
Provisions for doubtful debts increased to eight million pounds.疑账准备金增加到八百万英镑.
He felt very doubtful of the outcome.关于结果他感到非常疑惑.
I am doubtful whether it is true.我怀疑那是否真实.
It is doubtful if dehydrated fruit will make much headway.脱水水果是否有多大进步尚难予料.
It is doubtful that he will come.他会不会来值得怀疑.
As soon as he finished, his supporters applauded vigorously, but most of the masses were taken aback and exchanged doubtful glances.他的话完了, 他的几个支持者拼命地鼓掌, 而更多的人却噤若寒蝉,面面相觑.
Let's try to clear up our difficult and doubtful points.让我们设法把难处和疑点解决一下.
The day is doubtful.胜负难料.
I'm doubtful where to go.该往哪里去我心中无底.
The speaker was clearly playing to the gallery when he uttered so many doubtful jokes.演说者讲了这么多似是而非的笑话,显然是迎合低级趣味.
A doubtful Passage in a Latin Poet.
出自：AddisonThe question whether certain doubtful forms should be ranked as species or varieties.
出自：C. DarwinIt was doubtful if he knew who Andrew Jackson was.
出自：Scott FitzgeraldA change which is not an unquestionable improvement is a doubtful blessing.
出自：E. F. Schumacher
