Chinese ⇄ Arabic English French Russian

多年冻土 duōnián dòngtǔ
gen.	ever-frost
bridg.constr.	perennially frozen soil; permafrost soil; permanently frozen ground; ever-frozen ground
desert.	everfrost; perennially frozen ground
eng.geol.	perennial frost; perpetually frozen ground; perpetually frozen soil
hydroel.st.	permafrost
railw.	permafrost (soil)
soil.	pergelisol; permagel
tech.	eternal frost; ever frost; tjaele
多年冻土冻结状态持续三年以上的冻土 duōnián dòngtǔ
expl.	perennially frozen soil

多年冻土: 21 phrases in 5 subjects

Bridge construction	7
Desert science	1
Engineering geology	2
Rail transport	1
Technology	10