Problem: How does the sentence end?

When at the bookstore, Emily bought a comic book for Natalie because 
Answer: Natalie liked the surprise.

Problem: How does the sentence end?

Kayla wanted to start a business in a field that Felicia was working in so 
Answer: Kayla asked for some help.

Problem: How does the sentence end?

The medication failed to treat the disease and doctors were in a panic because the 
Answer: disease was resistant.

Problem: How does the sentence end?

Benjamin told Lawrence that he would volunteer to calculate the company's retained earnings.  
Answer:
Lawrence was grateful.