stratum

英 [ˈstrɑːtəm]

美 [ˈstreɪtəm]

n. 层; 岩层; 地层; 阶层

复数：strata　

Collins.1 / BNC.8071 / COCA.11902

牛津词典

noun

N-COUNT 社会阶层
Astratumof society is a group of people in it who are similar in their education, income, or social status.
1. It was an enormous task that affected every stratum of society...
  这是一项影响到社会各阶层的重大工作。
2. The rebels came overwhelmingly from the poorest strata of rural society.
  叛乱分子绝大多数来自农村的最贫困阶层。
N-COUNT 岩层
Strataare different layers of rock.
1. Contained within the rock strata is evidence that the region was intensely dry 15,000 years ago.
  岩层中有证据表明，该地区在 15,000 年前曾经非常干旱。

noun

an abstract place usually conceived as having depth
1. a good actor communicates on several levels
2. a simile has at least two layers of meaning
3. the mind functions on many strata simultaneously
Synonym:levellayer
people having the same social, economic, or educational status
1. the working class
2. an emerging professional class
Synonym:classsocial classsocio-economic class
one of several parallel layers of material arranged one on top of another (such as a layer of tissue or cells in an organism or a layer of sedimentary rock)

The population is divided into strata and a random sample is taken from each stratum.
总体分成阶层后由各阶层抽选出来的随机样本。
And it also can remain in the stratum corneum, exacerbating irritation.
而且它还会遗留在角质层中，加剧对肤质的刺激。
Let us choose a particular social stratum.
让我们挑选某个特定的社会阶层。
This is a stratum we must win over.
这一阶层，我们是必须争取的。
They found a stratum of coal thick enough to be mined with profit.
他们发现了含有厚到可以开采并获利的煤矿的地层。
An identical soil stratum may exhibit elasticity, elasto-plasticity or visco-elastoplasticity under different modes of groundwater changing.
同一土层在不同的水位变化模式下可表现为弹性、弹塑性或粘弹塑性的变形特征；
It was an enormous task that affected every stratum of society
这是一项影响到社会各阶层的重大工作。
This evolution is stratum accumulation but not replacement.
这种演进是“层累”式的，而并非是“替换”式的。
Tramps are from the lowest stratum of society.
流浪汉来自社会最下层。
They do not constitute a separate class or stratum.
知识分子和青年学生并不是一个阶级或阶层。