Is rust a pure substance or a mixture? < 3

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Read these sentences from the text. near the equator, the tropics receive the most rain on a consistent basis. as a result, the fresh water falling into the ocean decrease the salinity of the surface water in that region. [. .] . . as the salt content of sea water increases, so does its density. what can you infer about how rain affects the density of surface water near the equator?

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?