Problem: How does the sentence end?

At the music shop, Sarah bought many vinyls even though CDs were in stock because the 
Answer: vinyls were of higher quality.

Problem: How does the sentence end?

Nick decided to leave the band, while Eric remained, because 
Answer: Eric was happy with the other members.

Problem: How does the sentence end?

The soldier tried to put the harness on the chest of the dummy but the 
Answer: chest  was too large.

Problem: How does the sentence end?

Erin  went bankrupt quickly while Laura prospered, as 
Answer:
Erin was incompetent at doing business.