[Q]: How does the sentence end?

It was easy to see that Erin but not Sarah was a good waitress because

[A]: Sarah received a few tips just once a week.

[Q]: How does the sentence end?

The star that was visible from the house was brighter than the light from the moon. The

[A]: Moon was darker.

[Q]: How does the sentence end?

This was Brian's first child but not Donald so

[A]:
Donald had an idea what to do with the contractions.