I agree with it in principle but I doubt if it will happen in practice.

我原则上是同意它的，但我怀疑在实践中它是否会发生。

《柯林斯英汉双解大词典》

I have family and friends who have had swine flu, though I doubt if they appear in the figures.

我有家人和朋友感染了猪流感，尽管我怀疑他们是否出现在数据中。

youdao

I doubt if Kieth totally agreed to those yesses.

我怀疑基思是否完全同意那些看法。

youdao

"I doubt if you can understand how happy this modernizing has made me.

VOA: special.2009.12.07

Now, I doubt if there's anybody here who is indifferent between the choices, indifferent with regard to the choice between these two lives.

我怀疑这里不会有人,会对这两种选择无动于衷，大家对这两种生命选择都会有所感触。

耶鲁公开课 - 死亡课程节选

So, when in doubt, if you're having some weird character issue, odds are you need to escape it in some way.

如果你有拿不准的字符,可能就要用到转义字符了。

哈佛公开课 - 计算机科学课程节选

Alas, I doubt if President Obama would nominate Bair or the Senate would confirm her.

FORBES: Sheila Bair For Treasury Secretary

The smokers can still bring individual cases but lawyers on both sides doubt if many will.

ECONOMIST: Ups and downs for Big Tobacco

No doubt if Mr Kennedy had come on board, the criticism would have been more muted.

ECONOMIST: Intelligence