This article discuss the method to avoid the eutrophication problem of water body from the digging up the lake sediments which may lead to destroying the blance of nitrogen and phosphorus in water.
从底泥挖掘可能导致水体营养元素平衡破坏的成因入手，探讨避免水体富营养化加剧的对策。
The printer changes the traditional method acquiring the check-up date and number by lead letters radiated by X-ray in routine radiograph and makes check-up date and number regular and clear.
改变常规X线照片用铅字经X射线照射获得检查日期、检查号（片号）等信息的传统方法。
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