Sentence examples for challenges are that from inspiring English sources

"I think the challenges are that quite often you would never take over a job when the team is so good," Moyes said.

I wonder what some of the challenges are that you face in encouraging entrepreneurship in Nigeria.

The three big challenges are that solar cells are expensive to produce, they're not very efficient, and you need some means to store the energy collected.

The always excellent IEEE Spectrum has a great article right now that is both a primer for current chip manufacturing techniques and a look at what the challenges are that chipmakers are facing.

To be precise, the challenges are that (a) non-text regions have similar colors or intensities to the text pixels and hence the conventional methods fail to classify them correctly and (b) these misclassified pixels corrupt the statistics that will be used in text and non-text classification.

This last may not be a rhetorical question, since we may have more control than we think, once we figure out more clearly what the challenges are that we face.

"The big challenge was that beautiful dog," he said.

A more stringent revegetational challenge is that following strip-mining.

The challenge is that essential medicines often run out long before the next supply is due.

The most challenge is that flow regime around horizontal wells is not constant.

How challenging was that?