It is important for drainage work since checks can be made on its effectiveness before planting . 排水工作很重要，因为在栽植前就可对其效果加以控制。
It became necessary to provide drainage or sewer systems to carry such wastes away from the area . 提供排水系统或污水管道系统，把废物排出市区已成为必要。
Improvements in drainage and fertility levels are in themselves methods of reducing the incidence of some of these weeds . 改进排水和肥力水平本身就是减少某些杂草生长的方法。
The sludge is passed under a vacuum pump and allows the water to pass through a discharge or recirculation drain . 用真空泵除去污泥的固体含量而该泥水则经排水渠或回流渠排出。
The displacement method, on the other hand, can be used to obtain accurately the cubic volume of any part of the tree . 另一方面，排水法可用来精确求得树木任一部分的立方材积。
It is important that the land be well drained when fall planting is practiced in order to prevent soil heaving during winter . 更重要的是在秋栽时要排水良好，以防冬季土壤冻胀。
On either side a checker of open ditches showed where the municipal constructors had designed a system of drainage . 马路两旁纵横交错的阴沟说明承包市政工程的商人曾计划在那里修建排水系统。
The chemical reactivity of apo would prevent the parent compound from reaching the discharge water of a treatment plant . 三嗪基膦氧化物的化学反应能力会阻碍废水中原有的化合物到达处理站的排水中。
In drainage of agricultural lands, a filter or gravel envelope is used to prevent the entrance of fine sand and silt into the drains . 在农田排水中常常采用砾石或过滤层来防止粉细砂和泥沙进入排水沟。
The disinfection of the combined sewer overflows 合流制排水系统溢流污水消毒处理
