Question

i scan their faces, trying to look as placid as possible. in the sentence above, placid has the same or almost the same meaning as: arrogant mysterious unruffled intimidating

Explanation:

"Placid" means calm and peaceful. "Unruffled" also means calm and not disturbed. "Arrogant" means having an exaggerated sense of one's own importance. "Mysterious" means difficult to understand or explain. "Intimidating" means making someone feel frightened or nervous.

Answer:

unruffled