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....
I heard a peal of merry laughter.我听到一阵响亮的欢笑声。A peal of church bells rang out in the distance.远处响起了一阵教堂的钟声。The bells of the cathedral rang out their loud peal.大教堂响起了响亮的钟声....