13: We have math .................... Tuesday morning.

A. in                      B. at                     C. on               D. of

14: ................ racks have magazines and those have newspapers..

A. This                    B. That                C. These               D. There

15: Washington DC is the .................. of the USA.

A. city                    B. capital                 C. country             D. street

16: In .................., we study the world rivers and mountain ranges.

A. English                  B. Physics              C. Music        D. Geography

17: They talk ............ their class and friends.

A. at                     B. on                  C. in             D. about

18: In Geography, we study different countries and ........ people.