stratum

1. N-COUNT A stratum of society is a group of people in it who are similar in their education, income, or social status. 社會階層[正式] [usu with supp]

It was an enormous task that affected every stratum of society. 這是一項影響到社會各階層的重大任務。

2. N-COUNT Strata are different layers of rock. 巖層[技術] [usu pl]

Contained within the rock strata is evidence that the region was intensely dry 15,000 years ago. 巖層中的證據表明該地區(qū)在15,000 年前曾經非常干旱。