[Q]: How does the sentence end?

Jennifer came limping into work but not Rebecca because 

[A]: Jennifer had worked out too hard.


[Q]: How does the sentence end?

The puppies had weak eyes but sharp ears because the 

[A]: eyes develop much slower in growing animals.


[Q]: How does the sentence end?

Unlike Rachel , Erin offered her heart to those who suffered, because 

[A]:
Rachel was so selfish.