Answer: Yo soy optimista
I am optimistic
Explanation: The subject in this sentence is "Yo", that is a first-person in the singular, so the verb must be conjugated in this form. Yo soy.

yeah yeah yeah yeah yeah yeah
yuh yuh yuh yuh yuh yuh yuh yuh
ye ye ye ye ye ye ye ye ye ye ye
ehehehehhehehehehehehehehe
:D
Answer: because of the changed border, many Mexicans became Americans. Many Mexicans defected from the Mexican military to live in the U.S. Many Mexicans were captured by the U.S. military and forced to live in the U.S.
Explanation: