Answer;
We can't bring anything in or out ,
Explanation;
-Nothing enters or leaves a closed system; for Earth, only sunlight enters and heat leaves. This means that limited resources cannot be replenished if growing populations consume them at too fast a rate.
-Another consequence is that wastes can accumulate more quickly than they can be disposed of. Environmental problems that have local or regional effects must be dealt with on a different scale—one that takes into account the scope of the given problem. Within a more restricted perspective, smaller areas are not necessarily considered closed systems.