Sentence examples for a difficult answer from inspiring English sources

How did Ms. Harris come up with such a location -- a place whose very existence would make a difficult answer in Trivial Pursuit -- having never been there?

An interesting theme that did emerge during the cognitive interviews was that caregivers reported having a difficult time answering many of the items.

This is a difficult question to answer, because the natural response would be some form of optimal control; for example, solving the Bellman equation using backwards induction.

That is a difficult question to answer.

That's a difficult question to answer.

"It is a difficult one to answer at the moment".

A difficult question to answer at this point.

"I find that a difficult question to answer.

J-YF: That's a difficult question to answer.

I think that's a difficult thing to answer.

Why reaction time should improve is a difficult question to answer.