Problem: How does the sentence end?

Mary slept on the cot instead of the bed at her friend's house because the 
Answer: cot was new.

Problem: How does the sentence end?

Getting good grades at school was easier for Tanya than Elena because 
Answer: Elena  didn't really like studying.

Problem: How does the sentence end?

The meeting took longer than the interview because there was more to cover during the 
Answer: meeting .

Problem: How does the sentence end?

The comet slammed into the planet but had missed the satellite, so the 
Answer:
planet was destroyed.