实际输气管特点Actual characteristics of gas pipeline temperature drop:
A.
沿降速度较输油管快The temperature drop speed along the pipeline is faster
B.
下游管道温度低于环境温度The downstream pipeline temperature is lower than the ambient temperature
C.
沿降速度较输油管慢 The temperature drop along the pipeline is slower than that along the pipeline
D.
下游管道温度高于环境温度The downstream pipeline temperature is higher than the ambient temperature