Choose the correct phrase for each sentence

1. Being a nurse is very responsible and I love it, but I'm a bit tired of working at
   [get down to work|challenging work|freelance work|low wages|work long hours].
2. "Don't waste your time any longer. You have only two hours to finish the project.
   [Get down to work|Challenging work|Freelance work|Low wages|Work long hours], I'll check it when I'm back."
3. One of the difficulties of being a surgeon is that you can't have a normal work timetable. Surgeons mostly
   [get down to work|challenging work|freelance work|low wages|work long hours] and have little time to spend with their families.
4. I can't imagine working in an office and spending all my day there. I'd prefer to have a
   [get down to work|challenging work|freelance work|low wages|work long hours].
5. Teaching kids is a
   [get down to work|challenging work|freelance work|low wages|work long hours]. I don't think I could ever do that.