How does Wheatley use metaphor

Me plswhich is not a component of the sq4r method? recordrecitereviewreply

Your state government is planning to stop the payment of registration fees for senior school certificate examination (ssce) students in your state. write a letter to the governor, giving at least three reasons why the state should continue with this gesture of goodwill.

1. in which sentence is the underlined portion a predicate nominative? for astronauts, going into space to repair orbiting equipment becomes a challenge. for astronauts, going into space to repair orbiting equipment becomes tricky. for astronauts, going into space to repair orbiting equipment becomes challenging. for astronauts, going into space to repair orbiting equipment becomes frequent.