Problem: How does the sentence end?

Rachel didn't know how to be humble and Tanya did because 
Answer: Tanya tried to help people when needed.

Problem: How does the sentence end?

John bought the word processing software but couldn't afford a new operating system because the 
Answer: word processing software was inexpensive.

Problem: How does the sentence end?

Matthew had the image of Aaron burned into their mind, so 
Answer: Aaron was unable to hide his or her face.

Problem: How does the sentence end?

At the camp site, Mark was able to use the twigs to start a fire, but the branches didn't light. The 
Answer:
branches are wet.