[Q]: How does the sentence end?

We didn't get much sleep not because of the alarm but because of the siren since the 

[A]: siren was loud.


[Q]: How does the sentence end?

Laura always needed a companion, but not Felicia because 

[A]: Felicia didn't have a fear of being alone.


[Q]: How does the sentence end?

Complicated mathematical equations were easier to understand for Logan but not Kevin because 

[A]:
Kevin did not have an analytical mind.