He is in no doubt as to what is needed.

他对需要些什么心中有数。

《柯林斯英汉双解大词典》

If you are in any doubt as to whether you should be doing these exercises, consult your doctor.

如果你拿不准是否应进行这种锻炼，咨询一下医生好了。

《牛津词典》

Good compositions leave no doubt as to the subject of the photograph.

恰当的组成物毫无疑问需要对照片的主题有用。

youdao

"And as Iran's leaders continue to ignore their obligations, there should be no doubt: they,too, will face growing consequences.

VOA: special.2010.01.30

When I refer to my car as opposed to what we could doubt: the car stage or the car slice.

当我提到我的车,对照一下有疑问的地方：,车的阶段或者部分。

耶鲁公开课 - 死亡课程节选

I just want to make mention of this in case there's ever doubt, generally parentheses do solve your problem as an arithmetic but do realize this is some lower level details we'll come back to over time.

是想告诉大家如果你对某些式子的前后运算关系不确定，就加上括号,这都是一些小细节,我们以后还是会再提到的。

哈佛公开课 - 计算机科学课程节选

But there was some doubt as to whether the difference was any help to patients.

FORBES: Bristol Study Proves Rival Drug Better

The details in the article raised considerable doubt as to the veracity of the takeover bid.

FORBES: Congratulations Your Takeover Bid For Arsenal Arrived A Decade Late

The Independent on Sunday is in no doubt as to the significance of Mr Woodward's defection.

BBC: Defection dominates papers