No one has come up with a definitive answer as to why this should be so.

至于为什么该这样，还没有人给出明确的答复。

《柯林斯英汉双解大词典》

"No one has a good answer" as to why fertility varies among countries, says sociologist Andrew Cherlin of The Johns Hopkins University.

约翰霍普金斯大学的社会学家安德鲁·切尔林说，对于为什么不同国家的生育率不同，“没有人能给出一个好的答案”。

youdao

The answer is that no one has an easy fix for rising medical costs.

答案是，没有人能轻而易举地解决不断上涨的医疗费用问题。

youdao

But no one has the answer to how much market share Bing will claim from Yahoo or Google in the long term.

VOA: special.2009.07.17

No one has the definitive answer.

CNN: Yemen after Saleh: Still a treacherous road

No one has a precise answer.

CNN: What Saddam's got

It's a real dilemma and one to which the government has no good answer.

ECONOMIST: Bagehot