These Severn Valley woods have been exploited for timber since Saxon times.从撒克逊时代起就开始采伐塞文山谷的这些树林获取木料。The longest river in the United Kingdom is the River Severn.英国最长的河流是塞文河.They went up the Severn from Bristol to Glouces...
They went up the Severn from Bristol to Gloucester.他们向塞文河上游驶去,从布里斯托尔港到格洛斯特....a fortified arched bridge spanning the River Severn.横跨塞文河的加固拱桥One man spent months dredging the River Severn.曾有人在塞文河挖了几个月的泥.The longest river ...
Methane gas does collect in the mines around here.周围的矿井里的确有沼气聚积。The ignition of methane gas killed eight men.甲烷起火，致使8人丧生。Methane and propane are alkanes.甲烷和丙烷是烷烃。...