Which of the following are good conductors

iron, graphite,NaCl solution etc are some examples of good conductor of electricity

iron is because it is very important and powerful

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C. Birds following grazing animals who stir up insects

Explanation:Symbiotic relationships among organisms occur when they relate in a way that either one or both of them benefit from it.Symbiotic relationships may be classified as parasitic, mutualistic, or commensalism relationship. Commensalism occurs where an organism benefits from another organism without causing it harm.The best example of commensalism among the choices is when birds follow grazing animals who stir up insects. In this case, birds benefit by feeding on the insects without causing harm to the grazing animals. A parasitic relationship is where one organism benefits at the expense of the other causing it harm. For example, tapeworms living in a mammal's intestinal tract cause harm to the mammals.A mutualistic relationship is where both organisms involved derive benefit from the relationship. For example, bees pollinating flowers, the bees collect honey while the flower is pollinated for fertilization to take place.