Navigation within the document, and across its pages is facilitated by the use of standard keyboard shortcuts.
Use the arrow keys to move forward and backward through the checkboxes.
For example, use the down arrow to select the next answer, use the up arrow to select the previous answer. Please note that trying to move beyond the last answer with the down arrow key may position the cursor on the first answer.
Use the space key to tick a specific checkbox or radio button.
Press tab repeatedly to move to the check box area of the questions page. When this is successful, the first checkbox will be displayed surrounded by a box. Now to select the appropriate answer, use the up and down arrows.
Use the enter key to activate the currently selected link / button.
You can use the inbuilt browser functionality typically refered to as 'Zoom' to enlage the text or use the 'Ctrl' key and use the mouse wheel to zoom in and out.