The phrase "a certain level of knowledge" is correct and usable in written English.
You can use it when you want to indicate that someone possesses a certain level of understanding on a topic. For example, "He had a certain level of knowledge about molecular biology which allowed him to understand the research paper he was reading."
To create and appreciate satire in a messed-up world, you need a certain level of knowledge.
First, there has to be a certain level of knowledge about the history and nature of the conflict.
I've found that employers are interested in the content of my degree and that people expect a certain level of knowledge.
I could put a textbook in front of them with different perspectives on Mao and that would achieve a certain level of knowledge.
Parents have limited outlets for expressing their concerns and often have to muster a certain level of knowledge and clout to get attention.
The national qualification framework of a country requires a certain level of knowledge and complexity of skills for an academic degree to be recognized.
The rather sketchy narrative presupposes a certain level of Shackleton knowledge, so a little boning up beforehand is recommended.
Again, this course does not require a certain level of prior knowledge; it is suitable for students with varying levels of teaching, education, community partnership, and design experience.
Therefore, an increase in job autonomy during residency training will be expected by senior residents with a certain level of medical knowledge and skills.
Moreover, since all participating practices already had NHGDoc at their disposal, we presumed a certain level of basic knowledge about NHGDoc.
However, when directly asked, all patients in this study did acknowledge the need for a certain level of understanding, knowledge and ability to self-care.
