Sentence examples for has been a persistent challenge from inspiring English sources

Characterizing these patterns in forested ecosystems with remote sensing data has been a persistent challenge as variation in severity may be heterogeneous at fine spatial scales.

"This issue has been a persistent challenge for Pakistan," said a senior American official who deals with South Asia and who spoke on condition of anonymity because of the delicacy of the matter.

However, low protein yield has been a persistent challenge in further development of transgenic plants as a practical recombinant protein production platform.

Newborn mortality has been a persistent challenge, with reductions in neonatal deaths lagging behind declines in post-neonatal child mortality in most low-income countries.

Reversing the obesity epidemic has been a persistent global public health challenge, particularly among low socioeconomic status populations and racial/ethnic minorities.

U.S. poverty has been a persistent problem.

In Irbid, housing has been a persistent issue.

This has been a persistent problem for him.

Uneven performances, however, have been a persistent problem.

Christopher Plummer had been a persistent ghost in our home.

Infection prevention had been a persistent problem.