stratum

n. 地层，社会阶层

strangle, stranglehold, strangler, strangulate, strangulation, strap, straphanger, strapless, strapped, strapping, strata, stratagem, strategic, strategically, strategist, strategy, stratification, stratify, stratoscope, stratosphere, straw, straw poll (also straw vote), straw-coloured, strawberry, strawberry-mark, stray, stray away from, streak, streaker, streaky, stream, stream of consciousness, streamline, streamlined, streamlining, street, street credibility (also ,street `cred), street value, street-girl (also `street-walker), street-wise,