survey of existing line；survey of existing railway
Abundant existing species
access existing permanent file
according to existing law
account the existing infrastructure
adding extra-floor spanning existing building with steel structure
adding extra-floors spanning existing building
Adding storeys around existing buildings
additions to existing product lines
冷热电三联供系统（CCHP）
冷热电联供系统
热电冷联产(CCHP)
现有产品线的增加
Adjacent to Existing Line
advantages and existing problems
Already-existing Depletion Region
analysis of existing circumstance
analysis of existing condition
application of the existing facilities