氯用来给水消毒。Chlorine is used to disinfect water.给水加热时, 它会变成蒸气.When heated, water changes into vapour.可以毫不夸张地说,有成千上万座混凝土水坝正在供灌溉,给水 、 防洪 、 发电之用.Literally thousands of concrete dams are providing water supply shortage, irrigati...
His sporting and political interests coalesced admirably in his writing about climbing.他在写登山的文章中,把自己对体育和政治的兴趣完美地结合了起来。The puddles had coalesced into a small stream.地面上水洼子里的水汇流成了一条小溪。These two previously isolated species ...