林下更新  undergrowth regeneration

地下管线信息更新维护  maintenance of underground pipeline update

地下茎更新  Rhizome-wood regeneration

地下水更新  groundwater renewal

地下水可更新能力  groundwater renewable capability

短栅形天然下种更新法  Strip-method in echelons

冠下天然更新  Natural regeneration under canopy

上方天然下种更新法  Natural regeneration under shelter-wood

上更新统下限  the lower age of Late Pleistocene

生态约束下的采伐更新  cutting regeneration

天然下种更新  natural seeding regeneration; Natural regeneration

更新、更换  Renewal

上新更新世  plio-pleistocene

上新更新世界线  Pliocene-Pleistocene boundary

无刷新更新页面  updating Web

肝下下腔静脉  Inferior vena below the liver

上上下下  uphill and downhill; from cellar to rafter

视网膜下新生血管  subretinal neovascularization

水下[下水]滑道  under water launching way

水下新型堆  under-water reactor