雅思词汇之灭绝/污水/一次性的

　　extinction[灭绝]/dying out/termination/the mass extinction of[大规模灭绝]

　　-eg: This species of animal now is in danger of extinction.;

　　sewage[污水]-sewage disposal/purification/utilization[污水处理/净化/利用];

　　disposable[一次性的]

　　-eg: disposable products