Answer:
Yesterday and slowly
Step-by-step explanation:
Adverbs are words that modify verbs, adjectives or other adverbs by providing information of place, time, manner, frequency, degree or level of certainty. In the sentence, there are two adverbs: “yesterday,” which modifies the verb “work” by providing information of the time, and “slowly,” which also modifies the verb “work” and tells us about the manner Rachel worked.