Hola!! Me podrían ayudar a resolver este ejercicio de inglés??

Which sentence uses the past tense of to study correctly? a. mark is studying for his math test with margie. b. mark will study for his math test with margie. c. mark studied for his math test with margie.

It was a bitter cold saturday morning ,the young track star dressed for his daily five mile run

What do you think is the greatest invention that you use today? explain in 4 sentences