What type of literary device is “shut up! ”?

The development of new inventions in the field of space travel seemed rapid. how does the word rapid function in a sentence?

Excerpted from "the children's hour" by henry wadsworth longfellow a whisper, and then a silence: yet i know by their merry eyes they are plotting and planning together to take me by surprise. a sudden rush from the stairway, a sudden raid from the hall! by three doors left unguarded they enter my castle wall! look carefully at the lines above. a poem with this particular rhyme scheme is best read a. line by line. b. with long pauses. c. phrase by phrase. d. with a strong rhythm.

Which question does the adjective in bold answer? it takes less effort to write essays than you might think. a. how many? b. how much? c. what kind? d. which one?