[Q]: How does the sentence end?

Maria received a robin from Jessica at Christmas since

[A]: Jessica wanted to make the other happy.

[Q]: How does the sentence end?

Jenn removed the black mascara and put on some eye-shadow because the

[A]: mascara was tacky.

[Q]: How does the sentence end?

Christopher was very outgoing and so wanted to make a public speech but Michael dreaded it. This is because

[A]:
Michael was an introvert..