Answer:
a. I require money to live.
b. They did not find sufficient evidence to believe in the future.
c. It is tragic to bring about the destruction of a dream.
Step-by-step explanation:
The infinitive is constructed with the base form of the verb without any inflection connected to tense or subject. Thus, the sentences are rewritten with full infinitives, in which the base form is followed by to, in contrast with the gerund form of the original sentences. In that respect, one of the uses of the infinitive includes to indicate purpose, as in sentence A, while sentences B and C must be rewritten, since the gerund is originally used after prepositions and as the subject of a sentence.