The sentence "challenges are raised" is correct and can be used in written English.
You could use this sentence in a variety of contexts, such as talking about a difficult situation, an obstacle, or a potential problem. For example, you could say: "The test results showed unexpected issues, and suddenly, new challenges were raised."
However, two major challenges are raised for the classical CCA.
These challenges are raised in the face of climate variability and from growing environmental demands.
Similar challenges are raised throughout what was once the Soviet bloc.
As their standardization work in the 3rd generation partnership project (3GPP) and other organizations approaching to an end, challenges are raised by the new round of high demands of wireless traffic, which is spurring new radio technologies, deployment infrastructures and radio resource allocation methods to be studied.
However, some major challenges are raised as the clinical test of numerous ensuing nanomedicine products.
With regard to participants, important challenges are raised about community consultation and consent.
Their next challenges are raising money — they estimate each 300-person trial will cost $3 million to $5 million — and setting up a network of medical centers to run the trials.
In ancient times, skeptics challenged the claims of Plato and Aristotle and their followers, as well as those of the Stoics; and during the Renaissance similar challenges were raised against the claims of Scholasticism and Calvinism.
Furthermore, in this process multiple questions and challenges were raised that can be interesting topics for future work in cloud incident handling and in general security of a cloud environment.
While many challenges were raised, much encouragement was given, and it's clear there are plenty of people with a passion for growing healthy food.
