Sentence examples for been a difficult challenging from inspiring English sources

"If you reflect back on those five years, I think it's been a difficult, challenging, but nonetheless successful endeavor," he said in Baghdad, adding that "it's been well worth the effort".

Transforming the 1960s-built Commonwealth Institute building on Kensington High Street has been a difficult, challenging project and is the main reason that the opening is at least two years later than originally planned.

Industrialization of West Bengal has been a difficult challenge for successive governments.

"It's been a difficult challenge for me simply because I have to forgive myself for making an error.

"It's been a difficult challenge, and it's taking a little bit longer to get the business turned around than we expected," said Linda L. Ulrey, a Procter spokeswoman.

Thus, the in vitro tissue culture of the adult rodent retina has been a difficult challenge.

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

This is the nature of the so-called Inverse Bayesian Decision Theory (IBDT) problem, which has been a difficult challenge for analytical treatments.

Stigma in occupational health practice has long been a difficult challenge.

See related research by Vignon et al., The clinical evaluation of left ventricular (LV) diastolic function has been a difficult challenge.

The segmentation of MR images has been a difficult challenge often requiring either semiautomated or fully manual segmentation of images to separate bone from the surrounding soft tissues.