久青草国产手机视频免费观看_毛片网站是多少_亚洲视频中文_一区二区高清在线

contamination

英 [k?n,t?m?'ne???n] 美
  • n. 污染，玷污；污染物

考試真題

And it's not just dropping food on the floor that can lead to bacterial contamination.

2018年12月四級(jí)真題（第三套）閱讀 Section B