部分前循环闭塞
Partial anterior circulation
电路群闭塞的请求
Circuit Group Blocking Request CGB
开环-闭环基音提取
open-loop and close-loop pitch extraction
狭小密闭环境
limited and closed environment
活塞环的安装工具
piston ring installation tool
CCT国际环境的优化
optimization of CCT international environment