Answer:
1.immediately is the adverb. This shows the manner in which the boy left the room. It modifies the verb left.
2.difficult is the adverb because it modifies and shows how the test was like.
4.slowly and clearly are the adverbs. They show the manner which billy read.
5.fast is the adverb in the sentence which is adverb of manner. It shows how the person is walking.
3.Aloud is the adverb .It modifies the verb read and also shows how the teacher read the play.
6.quietly is the adverb in the sentence. It modifies the verb said and shows how the old man told his story.
7.uncomfortably is the adverb in the sentence. It modifies the verb is to explain how the weather is .
8.sooner is the adverb which shows time. Sooner modifies the verb return.
9.Happily is the adverb .This adverb modifies the verb looked to explain how the child was looking at the new movie.
10.often is adverb in the sentence which depicts how often the person writes to Lorrie.It modifies the verb write.
11.now is the adverb in the sentence. It shows the adverb of time and modifies the verb go.