A swarm of bees ( was ) hovering over the flowers.
The word 'swarm' is a collective noun & hence the singular form (was) should be used. It would have been 'were' if the word was 'swarms' as it indicates many swarms of bees together.
Referring to an excerpt from “I Explain a Few Things” by Pablo Neruda the correct choice is: By addressing the reader directly and asking the reader to see what is happening in Spain, the speaker reinforces his view that poetry could and should be used to inspire action—not just to describe beautiful things.
