In doing your working, which nation is the most impressive? = In doing your work, which nation is the most impressive? or In your opinio, which nation do you think is the most impressive?
You have been going around the world until now.
In the future, which nation will you want to go except the South Korea? = In the future, which nation would you like to go to except the South Korea?
Why did you choose this job? Did you have any opportunity?