By laying low and avoiding competition, stylonurines stuck around millions of years longer, while eurypterines were far more diverse and plentiful at their peak.

通过保和避免竞争，苯乙烯尿素存时间延长了数百万年，而广翅嘌呤其鼎盛时期更加多样化和丰富。

What throws a spanner in the works is the layer of polyethylene that makes the cup waterproof, and the lid, which is most often made of polystyrene.

工作中投入扳手使杯子防水聚乙烯层， 以及通常由聚苯乙烯制成盖子。