Problem: How does the sentence end?

It's better to use natural shampoo for your hair than synthetic shampoo as the 
Answer: synthetic shampoo is harmful for your hair.

Problem: How does the sentence end?

Nick needed a splint on their arm but not Michael because 
Answer: Michael had a healthy arm.

Problem: How does the sentence end?

Running in a marathon suited Nelson but not Michael because 
Answer: Nelson had practiced long distance running for years.

Problem: How does the sentence end?

Kim threw out the dairy from the refrigerator and kept the meat since the 
Answer:
dairy was spoiled.