[Q]: How does the sentence end?

Brian ignored Nick for forgiveness after having an affair since

[A]: Nick felt terrible about the situation.

[Q]: How does the sentence end?

Logan did better in the cooking class than Ian did because

[A]: Ian had less culinary knowledge and skill.

[Q]: How does the sentence end?

Aaron needs help from Neil with testing the specific gravity, because

[A]:
Neil is physicist and knows lot about specific gravity.