Maria should look in the engineering terminology book for the meaning of 'columns' or look in the dictionary for its technical meaning.
Explanation:
In the context, Maria who is referring an online text source, is reading about some engineering process. She comes across the word 'columns' which she believes she knew its meaning but she verify by looking the meaning of the word 'column' in an engineering terminology book.
She can also refer to a dictionary and look for its technical meaning. As in typography, the word 'column' means a vertical division of any page or the text. But in engineering, a 'column' may refer to a vertical pillar.
