"映画はなんで見ますか？"
- What do you use to watch movies?
- Where do you watch movies?
- What do you watch movies on?
^^^一般的（？）に言うと generally speaking
一つの映画
What did you use to watch it (the movie)?
Where did you watch it (the movie)?
What did you watch it (the movie) on?
アメリカ合衆国 
