Answer:
Several (adjective to students)
very (adverb to angry)
angry (adjective to students)
new (adjective to book)
Step-by-step explanation:
"Several" is a quantitative adjective to "students" which describes the number of students.
"Very" is an adverb to and adjective "angry" which describes the severity of adjective "angry"
"Angry" is an adjective to "students" which states and attribute of students.
"New" is an adjective to "book" which states an attribute of book.
"After" in this sentence is neither adjective nor adverb. It is conjunction. However "after" may be used as an adverb or an adjective in some sentences. For example, the lived happily ever after (adverb to lived), and, The area is observing aftershocks of the earth quake ( after as an adjective). In after years of our life, we never met.