The phrase "appear to be a challenge" is correct and usable in written English.
It can be used when discussing something that seems difficult or problematic, often in a subjective context.
Example: "The new regulations appear to be a challenge for many small businesses trying to comply."
Alternatives: "seem to pose a challenge" or "seem to be difficult".
With the increase of complexity of AC systems, the computational complexity of real-time optimization appears to be a challenge for practical applications.
That appeared to be a challenge to the Left-Greens and their leader, Steingrimur J. Sigfusson, a former truck driver and geologist with hard-left views who has served as finance minister since the caretaker coalition took office in January.
Especially for older workers, finding new employment after displacement appears to be a challenge.
In low- and middle income countries funding healthcare for informal sector workers has appeared to be a challenge.
The inclusion of poor and informal sector workers in these mechanisms appears to be a challenge that has yet to be addressed [5, 6].
There is a wider implication of all this, which is that maintaining ethical and legal standards in a sprawling global business appears to be a challenge (ahem) for a striking number of multinationals.
Introducing the healthcare financing mechanisms, which can reduce the burden of out-of-pocket payments to an affordable level for citizens, appeared to be a challenge in many low- and middle-income countries, including those in SEAR though it is a fundamental component of universal health coverage.
Self-care appears to be a challenge for so many of us, even if we aren't healing from a breakup.
Staffing also appeared to be a challenge to respondents in this study, as they specifically indicated working longer hours than is best for patient safety, and that they try to do too much too quickly in crisis mode.
However, external factors, such as the lack of skills and knowledge of professionals, seem to be hampering the implementation of AAC in school settings – a phenomenon that appears to be a challenge reaching beyond South Africa, as reported in other studies (De Bertoli et al., 2014; Kent-Walsh, Stark, & Binger, 2008; Pickl, 2011; Soto, 1997).
These statements tend to come from other members of the church who are uncomfortable with what, at first glance, may appear to be a direct challenge to leaders.
