You can move all elements using Drag & Drop. If you move the mouse over an element, the following Drag & Drop icon appears to the left of it:
Click on this symbol, hold down the mouse button and move the element to the desired position.
Info
Paragraphs can be placed under all headings, headings can only be moved with all paragraphs underneath (i.e. not between paragraphs under a heading), answers only to answers of the same question type, questions can be dragged under all sections, but sections can only be moved with all questions underneath (i.e. not between questions under a section).