Answer:
The sentences that contain an infinitive are:
1. Amy put in a lot of hard work to earn her bachelor’s degree in computer science.
4. It was Claudia’s childhood dream to write her favorite author’s biography someday.
Step-by-step explanation:
The infinitive is the base form of a verb, that can be used alone (the zero infinitive) or with to (the to-infinitive.) Infinitives can be used as adjectives, adverbs or nouns with the intent to indicate the intention of the action - like sentence 1-, as the subject of the sentence, to indicate what something will be used for, among other uses.