海底
seabed;sea floor; bottom of the sea
～地形sea floor relief /～采礦submarine mining; undersea mining; ocean mining/ ～電報(bào)submarine telegraph;cablegram/～電纜（線）submarine cable /～管理局seabed authority/～火山submarine volcano/～技術(shù)undersea technology/～架submarine shelf/～開發(fā)seabed exploration/～勘探submarine survey and exploration/～礦submarine mine/～爬行器bottom crawler/～區(qū)域seabed area/～山sea-mount /～生物benthos; benthon;bottom inhabitants/～實(shí)驗(yàn)室sealab/～水雷ground mine (or torpedo)/～延伸sea floor spreading/～養(yǎng)殖bottom culture /～油田offshore oilfield/～淤泥bottom silt/～資源seabed resources;submarine resources