Before the exam is an introductory prepositional phrase. Opal is the subject. frantically read and tried is the predicate or verb phrase. Frantically is an adverb describing how she read. Read, tried are both action verbs. And is a conjunction. "Through her notes" and "in her head" are also prepositional phrases. "To cram the information" is an infinitive phrase. "To cram" is the infinitive and information is the direct object.
I hope this helps! Nothing was underlined so I just identified everything.
