navigation [ˌnæviˈɡeiʃən] n. 航海
【扩】sailing 航海
sounding [ˈsaundiŋ] n. 水深度
porcupine [ˈpɔːkjupain] n. 箭猪
dredge [dredʒ] v. 挖掘
【搭】dredge sth. up 旧事重提
expedition [ˌekspiˈdiʃən] n. 远征
physicist [ˈfizisist] n. 物理学家
magnitude [ˈmæɡnitjuːd] n. 很多
topography [təˈpɔɡrəfi] n. 地形
crust [krʌst] n. 地壳
【派】crustal 外壳的
【扩】earth shell 地壳
【搭】earn ong's crust 谋生
rugged [ˈrʌɡid] adj. 崎岖不平的
tableland [ˈteibəl-lænd] n. 高地
【构】table（桌子）＋land（地）＝tableland（高地）
【扩】upland 高地，山地 highland 高地，山地
sediment [ˈsedimənt] n. 沉淀物
【扩】precipitate 沉淀物
* * *
A: Oh, there is some sediment in the bottom of the bottle.
B: Don't worry. It's pulp.
A：哦，瓶子底部有一些沉淀物。
B：别担心，那是果肉。
* * *
terrace [ˈterəs] n. 阶地
erode [iˈrəud] v. 侵蚀
noun [抽象名词]导航；航行，航海；航运，水上运输；浏览，访问；领航术，航海术；内河水道（尤指运河） - Pack ice around Iceland was becoming a threat to navigation.
noun [抽象名词]水深测量；测得的水深；意见调查，调查结果（常复数）；（铃或号的）发声 - There were 15 minutes between the first air raid alert and the sounding of the all-clear signal.
adjective [原级]发出声响的；虚夸空洞的，冠冕堂皇的；回响的，回荡的 - He needed a sounding board rather than thinking alone.
noun [抽象名词]英寻（测量水深单位，合6英尺或1.8米） - A fathom is a measurement of 6 feet or 1.8 metres, used when referring to the depth of water.
verb [vt. 及物动词]深刻理解，彻底弄清（难题或神秘的人）；测量（水）的深度 - I really couldn't fathom what Steiner was talking about.
verb [vt. 及物动词]vt. （用挖泥船等）疏浚；（用拖捞网等）捞取；（在食物上）撒（面粉等） - They dredge the bay for gravel.
verb [vi. 不及物动词]vi. 疏浚，挖掘；采捞 - Police have spent weeks dredging the lake but have not found his body.
noun [专属名词]挖泥船，疏浚机；拖捞网 - It is called dredge.
noun [专属名词]物理学家 - He's known to be an outstanding physicist.
noun [专属名词]（风格相同、互相连接的）排屋；（尤指房屋或餐馆外的）露天平台，阳台；<英>（足球场的）阶梯看台；梯田，阶地；<英>排屋中的一栋房屋；（地质）沿岸阶地，阶面 - Some guests recline in deck chairs on the sea-facing terrace.
verb [vt. 及物动词]使成阶地（或梯田） - ...massive terraces of corn and millet carved into the mountainside like giant steps. …
