pond scum

n.

（浮在死水上面的）绿藻类层；

Pond Scum
Pond Scum
Pond scum?
Pond scum to petrol :
Pond Scum Genomics: The Genomes of and
Worms, Pond Scum and Economists
Pipe Dreams Of Pond Scum
Algae: Is pond scum the next oil boom?
Pond scum to the rescue. Interview by David Biello.
Pond scum genomics: the genomes of Chlamydomonas and Ostreococcus.
Study of CuSO_4 Solution on Controlling Pond Scum
Releasing Stored Solar Energy within Pond Scum: Biodiesel from Algal Lipids
Genes for tight adherence of Actinobacillus actinomycetemcomitans: from plaque to plague to pond scum