Everything is open to challenge, questioning, and debate.

一切都是可以自由挑战、自由提问和自由辩论的。

youdao

A third presidential candidate emerged to mount a serious challenge and throw the campaign wide open.

第3位总统候选人上场郑重发出挑战，令这次竞选充满悬念。

《柯林斯英汉双解大词典》

One key challenge facing young scientists is how to be open without becoming scientifically vulnerable.

年轻科学家面临的一个关键挑战是，如何在科学方面不变得脆弱的同时保持开放。

youdao

"This is the challenge we have now: to open a lot of those doors."

VOA: standard.2009.08.15

It can be challenged on normal... Yeah, open to challenge. -Right.

一般情况下人们可以挑战。,对，人们可以挑战其中的观点，-是的。

普林斯顿公开课 - 人性课程节选

She added there were still legal avenues open to challenge the decision and she would now "regroup".

BBC: St Albans rail freight terminal approved

That said, any such change would be open to challenge in the courts.

BBC: EU: No limits on foreign players

And there are broader issues, especially to do with the aggregation of data and the handling of uncertainty, where his book is open to challenge.

ECONOMIST: ��The Skeptical Environmentalist��