From #4, " dust , stock and refuse conveyor systems" is listed separately from "hazardous exhaust systems". Although explosion relief vents are required when the stock, or refuse, is of an explosive nature, I can see no indication that "stock" can be read as "hazardous exhaust contents" - any more than refuse or dust can be. Hello everyone! I know that you generally use the verb “ dust ” as a way of saying “remove dust ” from a surface, for example, but if you want to use the word “clean” before, is it more appropriate to say “clean the dust ” or “clean dust ”? Thanks a lot! But in this context, the atmosphere is really positive and they are complimenting each other. I would like to know if the " dust the dirt off my shoulder" here means literally, that he looks cool just by brushing the dirt off his shoulder, or is there other meaning to this phrase? Thanks a lot for your help. Errors and uncertainties multiply, cascading upward through a chain of turbulent features, from dust devils and squalls up to continent-size eddies that only satellites can see. Here is my exercise materials of translation study, but I didn't get the meaning of the blue part. Could you rewrite or explain it in plain English for me? Thank you.