Problem: How does the sentence end?

James could not finish reading the book before the break ends. The 
Answer: book is pretty long.

Problem: How does the sentence end?

Donald liked to drink coffee and Jeffrey drank water because 
Answer: Donald prefered beverages with caffeine.

Problem: How does the sentence end?

Nelson is poor at doing analysis, while Christopher is great at it, because 
Answer: Christopher is an accountant.

Problem: How does the sentence end?

Hunter donated hair for a wig to Robert after their hair fell out because 
Answer:
Robert needed help and had no hair.