This person would have to be in 1990 B.C., because when in B.C., as the years go by, the number of the year gets lower. So the person was 10 in 1995 B.C., and 15 in 1900 B.C.
This could be the
1) insurance card or insurance information, which may be private insurer, Medicaid, Medicare, military health.
2) compared with your driver's license with current address
The answer should be pumice
The environment makes them intelligent because that’s why school was invented and being intelligent doesn’t run through genes