Read the sentences from The Riddle of the Rosetta Stone by James Cross Giblin. Next to the statues and the head, the slab seems unimpressive at first glance. It is roughly the size of a tabletop—three feet nine inches long, two feet four and a half inches wide, and eleven inches thick.

Which words in these sentences indicate an opinion?

eleven inches thick
roughly the size of
at first glance
seems unimpressive