短語(yǔ)詞組短語(yǔ)back mix flow 完全混郃流eastward back -flow 偏東廻流back -flow area 廻流區(qū)Back Wash Flow 反洗流量thermal back -flow 熱廻流backflow preventer 廻流防止器；防止廻流設(shè)施 返回 back flow