下层

lower levels; lower strata
【医】 substratum

1.lowercourse  2.substratum  3.sublayer  4.understratums  5.understrata  6.low-story  7.underseam  8.underlyingseam  9.lowerseam  10.subnatant  11.substory  12.subterrane  13.lowercoat  

下的英语翻译：

below; descend; down; give birth to; give in; go to; leave off; lower; next
take
【医】 cata-; hyp-; infra-; kat-; sub-

层的英语翻译：

layer; region; stage; story; stratum; tier
【计】 layer
【医】 coat; lamella; lamellae; lamina; laminae; layer; strata; stratum