Occasionally the text of a Web page is longer than your screen can display. To see the rest of the page, use the scroll bar -- often displayed vertically along the right side of the browser or horizontally along the bottom of the browser.
For a few quiz questions it might appear that the question is cut off or does not have a "Submit" button. The quiz pages are divided -- the top part for the questions and the bottom part for the answers. You may have to scroll down to see the complete page.