The part of the sentence "is complex and demanding" is correct and usable in written English.
You can use it to describe a situation, task, or other subject as being complicated and time-consuming. For example, "The engineering project has proved to be complex and demanding."
The challenges for society presented by climate change are complex and demanding.
despite the evidence that fatherhood has a long-term positive and protective effect on men's health, there is also evidence that fatherhood in the perinatal period can be complex and demanding.
However, combining the benchmarking process with a thorough and detailed process of indicator development could further improve the benchmarking, but will prove to be complex and demanding.
The care of patients suffering from cancer and especially those facing the death trajectory appears to be complex and demanding not only for student nurses but for professional nurses as well.
The voice production mechanism is complex and demand interaction of different systems of the human body.
Tuberculosis, malaria, and HIV exemplify host pathogen relationships that are complex and demand significant scientific elucidation at multiple levels from the molecular to the community.
Since the communication requirements of VANETs' safety applications are complex and demand high throughput, reliability and bounded time delay concurrently, the design of their MAC protocol is a challenge especially in high-density scenarios where the number of nodes contending for the channel use is large.
These tasks are complex and demand both a technical background and negotiation among stakeholders, who frequently present contradictory perceptions and aims.
The seemingly simple act of throwing a ball from the pitcher's mound to home plate is complex and physically demanding.
