Answer:
Scientists use the geologic time scale to illustrate the order in which events on Earth have happened. ... They used relative dating to divide Earth's past in several chunks of time when similar organisms were on Earth. Later, scientists used absolute dating to determine the actual number of years ago that events happened.
An isthmus is a narrow strip of land connecting two landmasses
I can't Understand you Sorry
The correct answer is - 3. maize.
The maize was the basis of the diet of the civilizations of Mesoamerica. It was one of the first wild plants in which the people from this region saw a potential as a big and stable food source, so they started to farm it. All of the civilizations we know from this region, like the Olmecs, Toltecs, Mayans, Aztecs, formed and developed their civilizations around the food source that was provided by the maize.