Problem: How does the sentence end?

At the park, the boy said hello to William but ignored Randy, because 
Answer: Randy was his enemy.

Problem: How does the sentence end?

Ian was not free at the time of the party but Donald was because 
Answer: Ian was very busy.

Problem: How does the sentence end?

Emily's thought her kitten had feline infectious peritonitis so she took her to the vet, Amy. Fortunately, 
Answer: Emily was told it was just a kitten cold.

Problem: How does the sentence end?

The publisher replaced his carpet floor with stained concrete over the winter months, the 
Answer:
concrete was trendy.