[Q]: How does the sentence end?

They did a lot better at the vocabulary compared to the grammar, because the 

[A]: grammar was more difficult.


[Q]: How does the sentence end?

Amy wanted a darker shade of paint than Mary so 

[A]: Mary didn't have to apply several coats.


[Q]: How does the sentence end?

Brian was able to afford the expensive watch at the store for Eric, so 

[A]:
Brian was generous.