The atmosphere had no oxygen it thereby created an environment where only anaerobic organisms could exist. They couldn't make there own food due to lake of oxygen in the atmosphere
13.99 kilometers is the diameter.
Divide the circumference (43.96) by 2(pi), which should give you a radius of 6.99. You should then proceed to multiplying that by 2, since radius is half of the diameter, giving you 13.99.
Friedman and Johnson (1997) show that for a wide range of dynamic optimization problems, supermodularity is both necessary and sufficient for monotone static results. In the present context, this implies that our supermodular model requires the minimum set of assumptions to obtain monotonicity in the optimal decision variables.
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The evidence presented here needs to be supplemented with information about inter- and intrafamily income transfers. This issue was addressed in a follow-up survey, but analysis of the results is not yet complete.