- 问题详情:WhentheAudetfamilyturnsonthelightsatBlueFarm,theyareusingelectricitythatcomesfromcows—cowmanure(粪肥),tobespecific.Cowsproducealotofwastes.Onecowcancreate30gallonsofwasteseachday.Nowimaginetheoutputofover1,000cowsatBlueFarm.That’sreallyabig...
- 20310