常見例句phenol and nitre content in groundwater of piedmont clinoplain were raising yearly , but totally keep in the range of first-level. 山前傾斜平原區(qū)地下水中揮發(fā)酚以及氮素含量逐年上升,但總體水質仍然保持在一級未受污染級別的范圍。Re sult shows :The surface water quality keep in the range of first-level in runoff formation area and piedmont clinoplain; 研究結果表明:瑪河徑流形成區(qū)及山前傾斜平原區(qū)水質一直保持在一級未受污染級別;Piedmont clinoplain 山前傾斜平原 返回 clinoplain