Please someone help me with this composition, I suck at English and I have it due to tonight

Suppose you need to verify how to correctly use commas. you open your english textbook and scan the chapter titles. in which one would you most likely find the information you need? ; ; ; ; that's the ? im having truble with

During editing and proofreading, you do not need to

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.