Arch dam is the safest of all water retaining structures.

拱坝是所有挡水建筑物中最为安全的一种.

1 construction industry: as cement mortar water retaining agent, retarder to make the mortar pump.

建筑业：作为水泥砂浆的保水剂、缓凝剂使砂浆具有泵送性。

The effects of seed dressing and base fertilizer with water-retaining agent on wheat growth were studied.

研究了保水剂拌种和基施对小麦生长的影响。

Water-retaining agent could improve the efficiency of water utilization through the effect on daily rhythm of photosynthesis rate and transpiration rate.

保水剂可影响光合速率和蒸腾速率的日变化进程，提高水分利用效率。

Application of water retaining agent is a key factor that results in the success of vegetative recovery of slope.

边坡植被恢复是在特殊立地条件下的植被恢复方式，水分是影响植被恢复效果和成败的关键因子。

The concrete faceplate and plinth upstream are key areas of water retaining and seepage prevention. The anti seepage effectiveness of face affects the imperious effect and the stability of the dam.

而此种坝型的上游面混凝土面板及址板是整个坝体挡水防渗的关键部位，面板防渗的好坏直接关系到大坝的防渗效果及其安全稳定性。