ЗАДТЬ ВСЕ ТИПЫ ВОПРОСОВ!)
They want to travel,to see the world from outside the Earth

Do they want to travel to see the world from outside the Earth? - общий
Do they or we want to travel to see the world from outside the Earth? - альтернативный
Why do they want to travel? специальный
They want to travel to see the world from outside the Earth, don't they? - разделительный
Who wants to travel to see the world from outside the Earth? - к подлежащему