名词
1. 社会阶层
A stratum of society is a group of people in it who are similar in their education, income, or social status.
2. 岩层
Strata are different layers of rock.
1. an abstract place usually conceived as having depth
e.g. a good actor communicates on several levels
a simile has at least two layers of meaning
the mind functions on many strata simultaneously
2. people having the same social, economic, or educational status
e.g. the working class
an emerging professional class
Synonym: classsocial classsocio-economic class
3. 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)