Question

select the infinitive or infinitive phrase.
in order to become an airplane mechanic, you need between one and three years of practical experience working with power plants or airframes, and you must pass several tests.

Explanation:

An infinitive is formed by using to followed by a verb. An infinitive phrase includes the infinitive and any modifiers or complements. In the given sentence, to become is the infinitive part. The phrase to become an airplane mechanic is the infinitive phrase as it has the infinitive to become along with its complement an airplane mechanic.

Answer:

to become an airplane mechanic