I would go with 'Major sandstorms destroyed the crops' because the Indus Valley civilization most likely declined by something affecting the food.
Maya used place value and zero in mathematics.
The Maya civilization was a Mesoamerican civilization developed by the Maya peoples, and prominent for its logosyllabic script, the most sophisticated and highly developed writing system in pre-Columbian Americas, along with its art, architecture, mathematics, calendar, and astronomical system. The Maya civilization developed in an area that comprised southeastern Mexico, all of Guatemala and Belize, and the western portions of Honduras and El Salvador.
Businesses compete in a free enterprise system because these systems exist in a capitalist environment, wherein the company with the "best idea" or product makes the sale and thus a profit--thus fostering competition.
plz mark me as brainliest :)
