周围的矿井里的确有沼气聚积。Methane gas does collect in the mines around here.废物腐烂时会产生沼气。As the waste materials decompose, they produce methane gas.目前我国户用沼气推广应用的规模上居国际首位.The application scale of digester is the first one in the world....
They may need some additional inputs and advice on how to improve the management of their farms.他们可能需要听取更多的意见和建议来改善农场的经营。In other cases, such as inventories, inputs and outputs are both continuous.在另一些情况下, 比如存货, 其投入和产出都是...