毫无疑问，这个错误是他的责任。

There's no ___question that the mistake was his fault.

这项新政策是否会改善教育状况尚有疑问。

Whether the new policy will improve education is open to ___question.

他最近的表现让人怀疑他是否适合升职。

His recent performance calls into ___question his suitability for the promotion.