a mountain of work的用法和样例：
- I have a mountain of work to do.
- I'm buried under a mountain of work so I can't go out.
- You do have a mountain of work to do?.....really?..... you go too far...
- She has a mountain of dirty clothes to wash.
- I'm sorry,I can't go to the movies with you this weekend. I'm buried under a mountain of work.