This is the 4616th most frequent Russian word.
демонстрировали
"Displayed" or "demonstrated."
The word 'демонстрировали' is used to express showing or exhibiting something to others, in this case, cooking skills.
Они демонстрировали свое умение готовить.
They demonstrated their cooking skills.
In this context, 'демонстрировали' refers to presenting artwork to the public as part of an exhibition.
На выставке художники демонстрировали свои картины.
At the exhibition, the artists showcased their paintings.
Here, 'демонстрировали' is used to mean explaining or showing how something works, specifically a teaching method, to an audience.