What name is given to this practice of using resources carefuly so that are future generation may also be able to meet their needs

poison levels are being represented and it show how much poison the producer has and how much the consumer has   and damage the organisms in it, particularly in the predators at the end of the chain. this is because accumulating compounds cannot be excreted.

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

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