Translation:I want to drive across all of Germany.
It can't be by plane since the plane doesn't go «че́рез Герма́нию», it goes «над Герма́нией». But train works.
My answer was 'I want to travel across the whole of Germany'. Struggling to see why it was considered wrong, but, looking down through the posts, I see others are in the same predicament. For the record, the 'correct' answer is not something any English speaker would ever actually say.