This is the 2255th most frequent Russian word.
заняли
"Took" or "occupied."
In this sentence, "заняли" refers to occupying a position or achieving a rank, specifically winning the first place in an event.
Мы заняли первое место в соревновании.
We took first place in the competition.
Here, "заняли" means to take possession or occupy a space or position.
Они заняли мои места в автобусе.
They occupied my seats on the bus.
Although slightly changed to "занялся," it carries a similar root and signifies dedicating oneself to an activity, in this case, reading.