Doporučuji
Earlier this year, I got a call from my son’s fourth-grade teacher that
he was being disruptive in class when it was time to do math.
She described that he would be unfocused and uninterested in what she was
teaching. But whenever she would call him to the board to do the math problem,
he would get it right. (source)
“In class” is an adverbial phrase like “at home”, “at school”,
“at work”, “in bed” etc.
However, in the specific case of “in (the) class”, you can use it with or
without the article if you're referring to a specific occasion, so:
- Yesterday the student disrupted the class …
(vyrušoval/vyrušil)
- Yesterday the student disrupted class …
(vyrušoval/vyrušil)
- Yesterday the student was disruptive in
class …
- Yesterday the student was disruptive in the
class …
- Yesterday the student was being disruptive in
class …
- Yesterday the student was being disruptive in the
class …
… and had to be taken out of the classroom.
Here's another Ngram.