[Q]: How does the sentence end?

Angela was diurnal while Erin was nocturnal so

[A]: Erin preferred to stay out late at night.

[Q]: How does the sentence end?

After Craig solved the difficult math problem, he showed Justin the solution.

[A]: Justin was proud of him.

[Q]: How does the sentence end?

Being physically intimidating came naturally to Kayla but not Sarah because

[A]:
Kayla was big and very muscular.