Sentence examples for problem has been challenged from inspiring English sources

The view that a broken cable would not pose a critical safety problem has been challenged by the National Transportation Safety Board, which insisted in investigations several years ago that the cables were crucial to flight safety.

Convincing scientists that there is a real problem with bias against women has been challenging.

Managing high temperature corrosion problems in biomass firing boilers has been challenging especially due to high amounts of chemically active compounds, in particular alkali chlorides.

But it has been challenging.

I know that cash flow is a problem for Rio and economically they've been challenged, but I think this is were sports need to step in where necessary to help and support each of their venues.

"ES96 was the class that gave me the motivation to be innovative," said Taci Pereira '17 of "Engineering Problem-Solving and Design," where students have been challenged to create anything from NASA flight instruments that measure ozone levels in the stratosphere to web applications that provide details on the acoustical characteristics of SEAS classrooms for the hard of hearing.

Both assumptions have been challenged.

Devising manufacturing/distribution strategies for supply chains and determining their parameter values have been challenging problems.

She says shining a spotlight on the problem has been a challenge.

Investigating the existence or non-existence of the limit cycle with order no less than 1 for models with state-dependent feedback control is challenging, but this problem has been addressed for some special cases [1].

This problem has been a long-standing challenge in developing countries, prompting consideration of water as a human right under international law.