How each subsystem affect the flow of matter and energy on earth?

My spanish teacher said this to me.. look at the ending on your verb. you need to make it agree with "yo" this is my sentence- sí yo estudiar español en la escuela how do i make it agree with "yo"

Marking ! 1-22 it's due tomorrow

¿qué cosas son parte de la cultura hispana de washington d.c.? a newspaper in spanish cultural foods of many different spanish-speaking countries music and instruments from spanish-speaking countries