The summer solstice is the first day of summer. This day, June 21, is the longest day of the year.
The early hominid stages can be differentiated from one another based on the complexity of the tools used by these species. The tool evolved along with the evolution of the humans. The more the hominids evolved by more complex their tools became. The tools made by the earliest hominids were used to fish out the termites. These tool developed and became more widely used as the humans evolved.
Hence, the answer is 'by observing the complexity of the tools'.
The answer to this question would be: Olive oil
In Mediterranean diet, you need to exchange the butter (since it contains unhealthy fat) with olive oil or canola oil. Saturated fat is also unhealthy so you need to exchange it. Lean meat is good but the consumption must be limited.