The first one is related to prepositions of time. You can have a look at the explanation (very graphic) and do the exercise below which has to do with travel. http://www.grammar-quizzes.com/preps_time.html.
The second one has to do with using prepositions for time and place. It is prepositions in context because you have a text to fill in about Michael Phelps, an Olympic swimmer. http://www.grammar-quizzes.com/preps_paragraph.html.
If you are more interested in prepositions you can press the different options at the top of the page.