How is the underlined prepositional phrase in this sentence being used?
he threw his books onto the top of the lockers.
adjective
adverb

Sample response: We had a great vacation! We went to a beautiful beach. The sand was white. We lay in the shade of the palm trees all afternoon, watching the butterflies and birds. In the evening, the ocean was very clear. We could look right down into the water and see coral reefs and bright fish. When I told my friends about it, they were all very jealous. They all said they wished they could have gone!

Explanation: