When you create a survey, every page becomes a numbered tab which is always placed between the Introduction and the End Text. You can move these small tabs either by clicking the arrows to the right or left (they show when you are in the respective tab) or by drag-and-drop.
If you want to move a question to another page, go to the tab ALL and drag and drop questions to the desired location.
If you want to change the position of questions which are on the same page you can easily do so with the arrows which show in the right margin when editing your survey.