Problem: How does the sentence end?

Jon had to attend more physical therapy for his knee than for his elbow. The 
Answer: knee had the more serious injury.

Problem: How does the sentence end?

It was simple for Robert to build a website but not Steven, as 
Answer: Robert was fluent in HTML and Javascript.

Problem: How does the sentence end?

It was easier for Adam to make good hiring decisions than Ryan because 
Answer: Ryan did not have any human resources experience.

Problem: How does the sentence end?

Samuel found yoga class much easier to do than Logan because 
Answer:
Logan was not very limber.