The plant produces a (great/large/huge) 'mass of' blossoms every spring. = The plant produces 'masses of' blossoms every spring.
The mayor is trying to encourage more commuters to use 'mass transit' in order to alleviate traffic in the city.
His policies are supported by 'the' (great/broad) 'mass of' the people. [=by most of the people]
(..) I imagine there were many in Rome who found that very entertaining. Was there ever a kind more obsessed with the obscene? People starve, the masses are enslaved, and Caesar answers with less bread and more circuses. But I can't complain. Their excessive nature lines my purses. (..)2016 Ben-Hur