流入湖中的泉水和河水携带了溶于水的硝酸盐和磷酸盐。Springs and rivers that drain into lakes carry dissolved nitrates and phosphates.硝酸盐是水和土壤中自然存在的化学物质。Nitrates are chemicals that occur naturally in water and the soil.硝酸盐由土壤渗入江河。Nitrates leach fro...
There is a dearth of good children's plays.目前缺少优秀的儿童剧.In our dearth of ack - ack guns all sorts of contrivances were used.在缺少高射炮的时候,我们利用了各种各样的巧妙方法....the dearth of good fiction by English authors.英国作家写的优秀小说少之又少Farme...