Sentence examples similar to it exemplifies a difficult challenge from inspiring English sources

It's a difficult challenge.

"It's a difficult challenge and that's what separates a lot of players, I think.

It is a difficult challenge to identify the functional effects of protein acetylation in specific pathways.

It's a difficult challenge, and one few of us might face in a lifetime.

"It is a difficult challenge but it is very exciting.

"It is a difficult challenge we've built it, brick by brick".

However, it has been a difficult challenge to culture adult rodent retina.

"We know it's going to be a difficult challenge," he added.

But this can be a difficult challenge.

Mr Penley faces a difficult challenge.

That's not a difficult challenge.